Which is why they used AI to mock these APIs for you... too? I'd expect Amazon to feed it a lot of internal information so it has more to work with than anything someone else can cook up.
I think having an interface with your AWS implementation and one for test mocks has always been great advice. With this though, it helps enable better integration testing too. I consider this a testing compliment, but if I had to choose one these days, integration tests are cheaper and better hang for your buck than ever.
I'll continue to choose both though, depending on the thing being tested.