if Microsoft has the power to give the keys to the feds what happens when Microsoft gets hacked?

Anyone as in "a single person". They don't mean everyone has access.

Sure. It's not anyone. It's anyone that can get a warrant. Or anyone that have enough power/underhanded influence to ask them nicely. Or any admin that have access to cloud storage at MS (remember they where caught with some exec having full access to that a while ago). Or any big leak that could exfiltrate these data. And probably a handful of other people, like, someone getting access to your MS account for whatever reason (which kinda happen, seeing how people lose their mail account to phishing/scams all the time) suddenly having access to your keys from there.

If your keys are in a DB somewhere, there's a lot of way they could get out. Would these ways coincide with someone actually having your drive at hand? Probably not. Still, the key not existing in plaintext in some third party storage close all these holes.

Anyone included Microsoft. You’re thinking of the word “everyone”

what happens when fydor monikov the sleeper agent from the kgb working at the fbi gets a copy of these master keys