A 'mistake' they are actually doing since a long time now. Here is the cups equivalent with a license change from apache to mit for the CUPS system.
https://github.com/microsoft/cups/commit/ad69bcc78bdea3fea3f...
https://github.com/microsoft/cups/commit/ad69bcc78bdea3fea3f...
Edit: To give a bit more nuance, I would guess that the actual bot changing the LICENSE files is not a mistake, but working as intended. What could, however, be a mistake is thinking that licenses can be legally overwritten. It wouldn't be a "rogue engineer" kind of mistake. Certainly several people at Microsoft have signed off on this.
That's not a bot.
https://github.com/microsoft/cups/commit/8100595a3a3a6d5c7d0...