I worked at IBM years back. If there's one thing that binds current and former employees together it was the shared stitch & bitch about the company's way of doing things.

That would frequently happen in large public slack channels and to my knowledge (first and second hand) nobody was ever punished for that kind of talk. However, that was internal, between employees. Often it was about frustrations with how the company was run, sometimes using satire.

If that sort of thing happened in front of a client (which I never saw personally), I firmly believe that person would rightly be shown the door. It's one thing to complain about your company's problems internally, it's another to publish them.