Mostly, if people do talk about social etiquette, it's within the context of not explicitly pissing people off, or looking good to your boss. I've never seen anyone talk about actually having good social interactions online.
I've had a few friends change jobs during the pandemic, and the thing they immediately tell me is that none of them have made any friends at work since starting virtually. They all just work on their own tickets, and whatever collaboration there is, is pretty transactional.
Zoom "happy hours" pretty much get dominated by two or three voices (usually of the most senior people) and everyone else just listens, because you can't have 2 conversations at a time. I've heard a bunch of the most cringeworthy techniques that managements have tried, to enhance socialization among employees.
In person, some things are pretty obvious. If someone is new, usually a good team will invite you into the conversation somehow. It would be weird if you got to your office and sat down and for days no one asked you anything about yourself. But it's perfectly fine to log into slack and have no DMs for weeks or even months.