They have to come back eventually if they want to access their gear storage and stuff, but the world travel between servers on the same data center was recently implemented and likely won't lose its appeal since some servers just have way more going in them than in others.

It's a bit sad, because it does impact overworld stuff in a big way. Like there's less people to do Fates, though the Fates do scale down. There's more people to take your server's hunt marks. If I were you, I'd find out the most popular server on your DC, and try out world travel yourself. Easier to bend in the wind instead of break and all that.