I have certainly seen people lean on friends or closer connections as sounding boards about things they are considering posting first.
Within the context of Discourse, this might look like sending a draft of the post in a personal message or in a direct message on chat.
Another idea coming to mind based on your ideation here is some kind of LLM based just-in-time feedback system – “you sure you want to post this?”
I don’t know how I really feel about that, but it’s hard to avoid thinking about where AI might fit into the picture these days. Perhaps if it were opt-in, it’d address this need though?