Yes, only AB and WSG. What I and a friend try to do is stand at the npc, get to screen where says to join and write 'now' or a letter or whatever so both click the 'join' close to each other.. Most of the time it works.
I had heard that a long time ago, you could join AV as a group but that was stopped and apparently you can as a guild or it seems like it because the other night there were a ton from a cross realm guild. However, not for the guild idea, they wanted to take over everything and did not want to allow other players on O. They said they would handle it. Most of us just ignored them and did what had to be done.