I suggested this in Triaging/reviewing/fixing issues and PRs. As I mentioned there, I closed a number of issues by linking to the “Why did changing list ‘y’ also change list ‘x’?” FAQ, usually after a shorter/personalized explanation.
This could be useful. We might also be able to implement it with autolinks (at least initially, if creating a bot is too involved), and have a reason-xxx that autolinks to devguide.python.org/faqs.html#reason-xxx.
Eventually having a bot/action that either edits the dev message or adds a new one with an explanation and a link to the devguide would be better.