So how do the maintainers and contributers know when a Discussion details a bug ready to be worked on? Seems like, as with issues, they'll still be sorting though them and looking for the most active ones?

Edit: after reading the contributors doc, it seems that feature requests are discussions which should help. Unreproducible bugs, too; although I would wager that a lot of users believe they can reproduce bugs but in fact can't consistently, or believe their feature request is a bug.

It seems this approach is better but still requires someone to sort through the discussions before they're moved to the cleaner issues pile.

One big pile with filters, or a chaotic pile and a clean pile. That seems to be the end result of this, unless I'm missing something.