I was privy to something while I still had a twitter account: a certain group of people, mostly anon or semi-anon accounts, having been brought into contact by some combination of algorithm, self-selection and serendipity, many of whom seemed to identify more with their emerging twitter ingroup than local circles, more than a few of whom self-described as very (if not terminally) online, self-organized a gathering IRL, which, while some seem to have had a good experience, quickly strained apparent bonds and revealed a number of fault lines

if this sort of thing is not unique to this particular group I could see it reinforcing the schism you describe, with online "communities" hesitant to talk to each other with goggles off lest it be discovered that a virtually established milieu may depend more on the avatars than the people behind them