Is hidden civs are default part of the most recent patch now? I don't think it's a very good idea, at least for Forest Nothing in the new players lobby, because too many people pick useless civs and you end up with no cutter on the team because only 1 out of 8 players picked a cutting civ.

We used allied vision a lot but I don't remember hidden civs being a part of that in every game, so I can only assume it's the patch?

Hidden civ is not a patch or mod or map feature, it's an option at Voobly what host can set (origins still by userpatch team). If you don't agree with hidden civs, then don't join those rooms.

hidden civs are OP!!!!!!!!