It just so happens that the Microsoft engineer who originally changed the license in GitHub went from Senior to Principal engineer at Microsoft in the past two months (according to LinkedIn). So you probably aren't far off.
If this is what happened, I suspect Microsoft will drop this person even quicker than a hot potato, and even quicker than if they told them to rewrite it from scratch but the person took a few shortcuts too many (which would be my guess).
If they wanted to fork it, they could - just keep the attribution and be done with it. The fact that they tried to rewrite it suggests that someone wanted it to be legally not a copy.
There is definitely a type of person who cheats, lies, throws people/teams under the bus, breaks the rules, and cuts corners to get ahead. The ones who are able to not get caught are rewarded.
This is not only a software phenomenon, but almost all aspects of life.
https://github.com/Azure/peerd/commit/473a26c808907f2d9f7b7f...
Unless they forked a very early version that did not even have the LICENSE file, such that they never removed the original notice, this looks like copyright infringement to me. That said, I am not a lawyer.
What does "chore" mean in this context? Is the license just leftover from some MS open source template? If so there is perhaps some leeway, and the author maybe just didn't realize he needed to use the original MIT license file including the notices and not just a template one grabbed from the internet.
Any other explanation for such a "relicensing" would be extremely worrisome.
Unless there was some "conspiracy" to violate the license (my original comment was an attempt at playfully hinting at that possibility, though I don't find it very likely), I'm sure the person who wrote that commit message thought about it for less than three seconds.