Some communities were unaffected. Some are still shut down. Some replaced mods who wouldn’t play by spez’s rules.
I’m not sure what the data would look like or how one would obtain it. Number of active moderators per day? Moderator satisfaction survey? Change in posting habits of top 1% posters?
I am speaking purely anecdotally from communities I know that shut down entirely and moderators who left. I have no way to estimate the scale of the exodus.