While I agree that the author is just whining about this situation and that AWS did nothing wrong, I'd argue that a change in defaults is a breaking change.
I don't think that's the case? AWS didn't fix a bug or removed some UB.
That's closer changing default key-binding. Anyways, all I'm saying - I would have considered it a breaking change because it changes default behavior.
Correct, I just would appreaciate that change in default behavior would be treated as a breaking change. It's really no that hard to grasp and many OSS projects treat it as such.