IMO the best perk seems to be the extra leggacy EoP contract. The whole thing is pretty worthless in the late game. We'll have to wait and see what these "exclusive events" turn out to be.

Here is Auxbrain's announcement: https://medium.com/@kevin_67107/egg-inc-goes-ultra-c70c306e2217

Email from a fellow Discord user

Extra coops have not started yet, they're waiting for more subs first.

Some screenshots I stole from Discord: