I wonder if Apple will just quietly send them off into the night never to be mentioned of again? I've seen a few pairs around, mainly on runners of all people but they don't strike me as popular or as convenient as the normal Airpods.

Without concrete figures you can always tell the popularity of something by how many units CEX stores have on their shelves and at what price. Its why they always have good stock of PS5 consoles at near-RRP pricing but very few Xbox Series S devices. If they didn't sell they'd be cheaper and a lack of stock normally means its rare, not popular but held on to.

They have loads of Airpods.