How many people (especially new users) actually read the help centerhelp center* banners?
I think the message in this banner should (also) be presented to the user when attempting to submit an answer (next answer? next n answers?). It should also be shown in a prominent way. Perhaps this could be limited to users below a certain reputation threshold, but even if it gets (temporarily) served to all users, I don't think it would be too much, given the current situation.
* When I wrote this answer the banner was only displayed on the help center page (or at least so I thought).