Unless they do major changes in how servers are set up, etc. I'd say server merges are out of the question for now.

Many servers are quite full - to the point where they have been declared congested and you can't get into them if you aren't already there. SE is currently trying to get people to move away from those servers and onto less populated ones.

Server merges are usually done when overall population gets too low. Right now FFXIV has rather the opposite problem, so new servers are more likely than merges.