@lopta I reset my password using the "compromised account" feature, since it just took a moment. Little to lose. However... I'm not convinced yet that there's a legitimate threat, so I haven't done anything beyond that.
(I don't use 2FA with Amazon because their 2FA support kind of sucks, and I don't have any "devices".)
It's easy for people to think they've found something serious and be dead wrong about it. I know this from the perspective both of someone who has raised a false alarm, and of someone who has to field security disclosures. So I'm holding this with some uncertainty, and I figure we'll know soon enough.