NO ONE, ANYWHERE, HAS SAID THERE WILL BE SERVER MERGES EXCEPT THE PLAYERS.
Why can you guys NOT get your heads wrapped around the concept of cross-server instances? Stop trying to read a ton of **** into this and looking for stuff to get bent out of shape about.
These changes will only affect you if you CHOOSE TO ENTER a cross-server instance to play with someone you want to who is on another server.