I was similarly confused when officially sanctioned GitHub project chose to use a non-github.com domain for their things. But then, we're talking about Microsof

I was similarly confused when officially sanctioned GitHub project chose to use a non-github.com domain for their things. But then, we're talking about Microsoft in the end here, who are famous for changing domains every N months at least, particularly when it comes to authentication services. Remind me, how many domains do you go through again when authenticating with online version of Outlook? Last time I looked, they send you through something like 4 different domains. And emails from Microsoft seemingly are on purpose sent from as many different domains as possible.