Returning to multiboxing - advice

[blast3r]

Hi everyone! I am coming back to WoW boxing and the last time I boxed was with Legion. I logged into my old account and have a lot of sub accounts I can use. But I only see an option to add a subscription and it doesn't tell me if I have to also buy the newer expansions. Anyone know?

Also, what server is everyone boxing on these days?

Edit: I figured it out. I was able to upgrade 5 of my accounts. Not cheap! I want to play Horde for the allied troll race so my old server wouldn't really work for me. Anyways, I'm good. Thanks