Do people actually do this in things like slack? (One of the best things about being a professor in a non lab field is that I don't have to use things like slack.) This seems like open contempt for the reader.

Yes all the time. Healthy conversations are shut down immediately with the "AI research" slop-wall.

Meetings are 55 minutes of speculating about what AI will be able to do in a few years. Then if you are lucky the last 5 minutes can be used to discuss a real issue.

I've never seen it, but I have a buddy who had a coworker like this. Would basically treat his slack as a manual copy-paste bridge to an LLM and it's was incredibly unhelpful because most questions were heavily context dependent.

I imagine this is the kind of thing you see at a large company where a good chunk of people are just coasting by doing nothing, Nelson Big Head style.