It definitely seems like this whole thing is known by maybe 5 individuals at Microsoft. It's not some big affront on open source software, they didn't relicense

It definitely seems like this whole thing is known by maybe 5 individuals at Microsoft. It's not some big affront on open source software, they didn't relicense the code under a less permissive license or anything, they just updated the copyright notice improperly. And that part I wouldn't be shocked was a single individual dev's doing. I agree, op should make a PR, state their case, and then complain if it's not merged.