It will be interesting to see what happens. The reality is that this disease is likely with us permanently in some form or fashion just like the flu - it mutates, vaccines against upper respiratory tract infections are notoriously difficult, and it has been around the world, and many who have it never know they are sick. So it will probably be endemic.
People aren’t going to accept indefinite restrictions on our freedom to congregate, especially young and healthy people whose personal risk is comparable to a regular flu. So count me as a skeptic that these haven’t returned by the end of the year. It may hasten the death of opera and the classics in live performances, as those audiences skew older and higher risk.
There was a car rave in Germany recently.
I would expect more strange and off beat events like that to start with before we get regular events, but they will return.