There are some theories suggesting that the Volantene fleet is not going to Mereen as most of the people think but to KL to overthrow whatever remains there and start a campaign to make a world empire. This would be a very GRRM-like move to shock everyone. Volantis is known to have desire of building a huge empire and just before the conquest, their last campaign was defeated by a united force including Aegon I.
If things are going like this, Braavos will be extremely upset about it because their archenemy will gain a massive influence. Besides if the Volantene succeed, Bravoos can say goodbye to their money lent to the IT, which is like casus belli for Bravoos. They by all means will try to put someone on the IT who will pay all the debts of IT (remember the speech between Stannis and Tycho) and also are prone to take new loans.
As a result, we may see another great war between the free cities. Bravoos politics is hinted in the POV's of Arya, and i expect we will see more of it coming. Participants from the Westeros or Slaver's Bay maybe even more interesting.
What do you think?