I assume AI only generated the readme file. But I would say if AI boilerplate eases Microsoft releasing more of their old code to the public, I am okay with that.

Microsoft recently closed a 7 year old .NET documentation bug I opened using Copilot. I am not a fan of AI but the submitted fix was far superior to the basically useless message that had been previously present, so net positive. At being ignored for 7 years, it was unlikely to get better from human effort.

I wouldn't assume that at all. If they're using AI for something as trivial as a readme, I think it is a very safe assumption that that's not all they're using it for.

I wish code repos had a "contaminated by AI" flag.