You'd be surprised. See. GP asks a very interesting question. And some grid infra indeed relies on AWS, definitely not all of it but there are some aspects of it that are hosted by AWS.

I worked for an energy tech startup that did consulting for big utility companies. It absolutely does.

do you know for sure? And if not yet, you can bet someone will propose it in the future. So not a weird what if at all

This is already happening. I have looked at quite a few companies in the energy space this year, two of them had AWS as a critical dependency in their primary business processes and that could definitely have an impact on the grid. To their defense: AWS presumably tests their fall-back options (generators) with some regularity. But this isn't a farfetched idea at all.