This pretty much says it . GRRM would never confirm or deny any questions in regard to plot before he has a chance to do it himself ... and he is King of the Cagey Answer. If it's a very direct plot question, you'll get something like "Keep reading ..", or "You think he's dead, do you?" If it's a more involved question, or one that could lead to a plot revelation, he'll honestly address the elements he can answer without giving anything away, and keep schtum about the rest.
Moving on... I agree with much of what Lord Varys says, but have some differences. I don't agree that it wouldn't be important to Hizdahr and the GG to have an heir from Dany. Hizdahr goes out of his way to point out his own ability to give Dany heirs.. when she has not so much as raised the question.. When the GG and Reznak are trying to convince Dany to be examined and eat the "special" cake, in the matter of the tokar, etc., it's clear that the getting of legitimate heirs is a concern for them. When the time came that Dany was no longer necessary, the hope would be that Dany's followers (in particular the Unsullied) would feel loyalty to her child, and thus be kept under control. I think they're really hoping to play a mid-to-long term game.
However, they are in a fluid situation and have to not only pay attention to their initial internal plans, but react to developments with the Yunkaii, the Volantenes, and so on. Skahaz says the pit changed all, and we can see that it did, not only with Dany's disappearance, but the death of Yurkhaz, etc.
Skahaz also says that when the Volantene fleet arrives, Hizdhar would throw open the gates. ... Well, by that time, Hizdahr might have, since he obviously never had real, total control of the city.. But that wouldn't have been in their original plan. I don't think we should underestimate the ambition of GG / Hizdahr, once they saw the oportunity to re-create a dynasty (possibly an eventual empire) through Dany. They have (and would still want) their natural alliances with the other slaving states, but wouldn't want to actually be "rescued" by any of them, for fear of a takeover.. They don't want Meereen to become anyone's satellite or client state. If any one state is to become predominant in Slaver's Bay in the long run, they would want it to be Meereen.
All of Hizdahr's off-page visits to the various pyramids were not to persuade the SoH to cease operations ... nor, in my opinion, were they merely for show. I think he was probably convincing the other masters that a royal marriage was their best move and that in spite of their own noble lineage, there was no use putting themselves forward - he was the only consort Dany would accept ( and of course the GG would back him up).
I know we're led to see Skahaz as a dreadful torturer, but I think he's probably not unusually so. We never actually see any of his interrogations. But .. we know that Barristan refuses to go along with him until he can interrogate the confectioner himself. That also happens off-page .. but since we next see him co-operating with Skahaz we can assume he must have been satisfied that there was reason to move against Hizdahr .. Would he have been convinced, if the confectioner had shown signs of being tortured to the point of saying whatever his questioner wanted to hear ? I don't think so.
We don't know what caused the enmity between Kandaq and Loraq, or whether it's of long duration, or not. From Skahaz' opposition the the slavers, I think it's reasonable to speculate that his family was not directly involved in the slave trade.(His pyramid is modest, and the GG seems to make a class distinction between Loraq and Kandaq.) We're really given no obvious clue as to what Kandaq's enterprise was, but we might see a hint in the olive groves outside the walls of Meereen that were destroyed as Dany approached. We don't know who was the originator of that plan. The text points out that it takes about 30 yrs before new trees become really productive. This, or something like it, might be enough to generate the extreme animosity of Skahaz (especially if there was loss of life to his family in the process). Even if you owned slaves to tend your orchards, what use would that be, if the orchards were destroyed ? Rather than an asset, they would become an added liability.... But that is just a speculation.
Skahaz is a blunt man, in general, but he's more than just blunt in his vehement hatred of Hizdahr .. This seems to me to speak of a more recent rather than long past cause for offense.
Early on, when Xaro offers his ships, the Meereenese don't want Dany to leave, because she would leave them vulnerable at that point.
Reznak mo Reznak gave a piteous moan. “Then it is true. Your Worship means to abandon us.”
He wrung his hands. “The Yunkai’i will restore the Great Masters the instant you are gone, and we who have so faithfully served your cause will be put to the sword, our sweet wives and maiden daughters raped and enslaved.”
“Not mine,” grumbled Skahaz Shavepate. “I will kill them first, with mine own hand.” He slapped his sword hilt.
Reznak plays on Dany's sympathies.. but since he is no doubt allied with the GG, this is not a real, personal fear on his part. If the great Masters were restored, Reznak, the GG's catspaw, would be alright. It would be a real fear for Skahaz and I don't think he's exaggerating... Perhaps the exchange should be looked at in light of Tyrion's later thoughts on slavery ... there is always a choice, even if the only alternative to slavery is death. If he's being honest here, Skahaz is very unlikely to act against Dany.
He's ambitious, but I don't think he ever thought of marrying Dany until...
Reznak and the Green Grace had been urging Dany to take a Meereenese noble for her husband, to reconcile the city to her rule. Hizdahr zo Loraq might be worth a careful look. Sooner him than Skahaz. The Shavepate had offered to set aside his wife for her, but the notion made her shudder. Hizdahr at least knew how to smile.
I think Skahaz' offer is one made in desperation, to thwart the GG's plan, or he would already have set aside his wife and been wooing Dany.
Obviously he has ambitions, allying himself with Dany from the outset, but if any scenario such as the olive grove postulation is true, allying with Dany may also have been his one opportunity to save his family from impoverishment (perhaps leading to eventual enslavement) without Dany's presence.
Unless Dany changed her mind again and decided to stay permanently, he knows that she eventually intends to leave for Westeros. He may well feel that he would be the best person to fill that power gap (and I might agree with him). He may have it in for Hizdahr personally, but impersonally, he also wants to break the power of all the great masters ("slavers all"). He has no ambition to be one of them.
I agree that while Skahaz may be in a position to betray Barristan and Dany's forces at the upcoming battle, there is no discernable advantage to him in doing so.
But I want to bring this back to the abortifacient issue. I don't know why so many readers want to write the idea off, when it clarifies the situation considerably. It's fairly obvious that the events at Daznak's pit and Dany's disappearance threw the proverbial spanner into the works for everyone. Dany's death would have done the same. No-one's plans were in a secure position at that point.
And there is so much in the text pointing to Dany's fertility.. the abundance of fertility symbolism in her dinners and meetings with the GG, Hizdahr and Daario and whether she partakes or not.. the desire for heirs on the part of Hizdahr and the GG.. the likelihood that she does, in fact, miscarry later.. and the great similarity between her symptoms and actions and those of Belwas.
Belwas doesn't throw up right away. Even after he finishes the locusts, there is at least one other bout in the pit (the youth), at least two beast fights, a mock battle and Tyrion and Penny's folly before the program gets around to Barsena and the boar, when Belwas begins to vomit..
When Dany eats the green berries, George first has Dany equate them with spice and gives them a bitter aftertaste, such as would be masked by honey ...
Dany squinted at them suspiciously, then plucked one from a branch and nibbled at it. Its flesh was tart and chewy, with a bitter aftertaste that seemed familiar to her.“In the khalasar, they used berries like these to flavor roasts,” she decided. Saying it aloud made her more certain of it.
Her belly rumbled, and Dany found herself picking berries with both hands and tossing them into her mouth.
An hour later, her stomach began to cramp so badly that she could not go on. She spent the rest
of that day retching up green slime.
We follow her through a violent purging of her system into exhausted sleep, and when she wakes she realizes she's bleeding...
Am I dying? Then she saw the pale crescent moon, floating high above the grass, and it came to her that this was no more than her moon blood. ... ... She was bleeding, but it was only woman’s blood. The moon is still a crescent, though. How can that be? She tried to remember the last time she had bled. The last full moon? The one before? The one before that? No, it cannot have been so long as that.
Her period is out of sync with her regular cycle, and she seems to have missed one or two.
The fact that GRRM has her wonder if she is dying before he goes on to "only a woman's blood" and then on to strongly imply that she has aborted, I think is meant to hint at the intent of her poisoner, as well as her status.
ETA: I think there is a parallel to be made between Meereen and the situation at Winterfell, but GRRM places our sympathies a little differently.
The Bolton's have taken WF, the northmen want him out - and though they've allied with Stannis, they don't really want Stannis to have the rule of the castle, or the right to dispose it where he will.