A norm of "don't be a dick" isn't inherently a violation of free speech. The question is, does LW co-working chat have a norm of not being a dick? Would being a dick likely lead to unfavorable reactions, or would objecting to dickish behavior be frowned on instead?
The problem with having "don't be a dick" as a norm is that people have very different ideas about what constitutes "being a dick".
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.