> There seems to have been a shift, somewhat, in the comfort level of different generations about saying things "out loud" in large public rooms.

I think this is merely the shift from doing this as a hobby, to doing this for work. Random coding problems mixed with banter I posted or answered on IRC back in the day? Purely hobby stuff, things I done after school instead of doing my homework. No stakes beyond the community itself, I could disengage at any moment, nobody would care - there was no commitment of any kind involved.

Today? Even if we switched back from Slack/Teams/whatnot to IRC, the fact remains, the other people are my co-workers, and we're talking about work, and it's all made of commitments and I can't disengage, or else I starve.

That changes the dynamic quite a bit.