Oh yeah, I'm not arguing against your idea. It would need to be implemented per game anyways, so the devs can decide themselves, whether they want their achievements to be suitable or not.

Having said that, maybe what you really want is a similar idea, which I saw pitched a while ago: Dynamic recaps.
Basically, the game would detect that you haven't started it in a while, so could offer a quick rundown of the controls. And if you're loading a save from a few months ago, it could offer a quick summary of your most recent milestones in the story / game progression.

So, yeah, pretty much your idea, but it's not re-using achievements for that...