'Stickying', 'Bumping', and 'have we moved on'?

Hey, that Markdown text-formatting document is really helpful.

If it were to be decided that should stay up front, how would that happen?

Also, in trawling through old threads, some seem still relevant, and I wonder about a way of 'bumping' them, other than just adding a comment at the end. (I could of course just comment "bump")

Also, some discussions are about perennial issues - such as 'Editing comments' or 'TL;DR's - but they're so old, I don't know how the discussion / design process has moved on since then.

The 'Editing comments' one I don't really want to bump, but a glance at the context box left me with the haunting question: are people getting notifications every time I edit a context box?

It says something great about this community that that thread is still open and that it's recently been linked to.

BUT
For some such conversations I'd like to flag to a Steward (if that's the right term) - is it time to start a process of saying, okay, we've moved on, we need to close the old thread, or at least make a new summary to seed a fresh conversation?