I'm not sure how playing in a bubble without fans means they are a ghost. Honestly I wish fans didn't come back to live sports. Hearing the game and player noise makes everything much more enjoyable. I think most pro-sports are currently doing great besides missing ticket revenue, especially compared to a few months ago when they weren't going at all.

Anyways, I don't think measuring recovery in the number of events and parties is a very good metric. Though I agree without that there probably isn't going to be true herd immunity for this and I wish people would stop throwing around the term.