GuildWars 2 - Server overflow to help friends connect and play together - this worked wonders for me and my pals.
WoW - Free character transfers to select low pop servers for friends to meet, connect, and play.
FF14 ARR - Sorry, we can't do anything

I am surprised they haven't thought of anything to actually HELP people play with their friends.
MMOs are meant to be played with your friends, whether you have 2 or 20. They should have thought of this scenario before the opening of Phase4 and EA. Put some sort of plan together, people want to play with their friends, that's the bottom line.

It would be nice if they did offer some sort of service for established players (lvl 25+ or whatever level) to leave high pop servers to low pop servers to play with their buds.
That's all I got to say about dat.