i.e. they could have emailed the author to ask:

1. "Would you rather us fork your project (new name), or would you rather donate your project to us under its original name, as well as give us the ability to rename it (which we will)"

2. "Would you like a $300 microsoft store gift card as thanks for writing some code we're planning to use?"

3. "Would you be open to providing a paid ($600 microsoft gift card) 1-hour consulting meeting to ramp our engineers up on your codebase? We won't actually listen since our engineers can in fact read, but we'll pay you"

4. "Also, just in case you don't know who microsoft is, we do have a careers page over here, and our team doesn't have headcount but other teams do <link>"

It sounds like microsoft didn't do any of that, which as you say is well within their right, but emailing to ask is polite.