Even if servers tend to "die" not like the possibly of a merge is ruled out. Might loose yours name though
/shrug.
Hopefully this game can just strive in the long run. Hope GF makes good decisions
A merge is not necessarily positive in every aspect.
If you are one of the few last players on a national server you have to expect to know nobody on the other server. That way you might find no guild which causes you to stuck in progression. It's not unlikely for MMO's to have pretty much closed communitys after some period of time. Of course there are a lot of if's but whatever.
It's just a lot saver to play on the 'global' server. That's just my personal opinion though.