Hey, having actually looked at the link you provided, in fact both examples they give are linearizations so they could plausibly be providing linearizability (with respect to a single key). It's hard to say whether there are corner cases in which different clients could observe different orderings but if not then I stand corrected!

There was another thread where somebody claimed it was causally consistent. I’m sort of surprised Amazon hasn’t been clearer about this, but my feeling is that they would say it was linearizable if they were sure it was linearizable. Would love to read a real deep dive on this, I checked to see if Kyle Kingsbury had looked into it yet but he hasn’t.