Has anyone been asked to leave a seated table after 2 hours because Aviary needed to honour other reservations? We were asked to go over to the standing tables if we wanted more drinks after the 5 course pairing menu. Is this common?

Yes. It is a common practice for them

Yes they need turnover, 2 hours seems reasonable to let someone else enjoy the experience. We gladly went to standing tablea and enjoyed watching drinks made.

We sat around until closing and no one asked us to move. I'm not sure if that's common but it didn't happen when we were there.