In the past, I've been in talks with an employer about a job, and my enthousiasm was only so-so, and that tended to put a brake on the proceedings.
I too have been in a similar situation (being interviewed at a startup and being clearly not super enthusiastic about the position being offered) but they decided to go with somebody else they gave me a courtesy call letting me know about it. I think it's the right thing to do.
I just think Microsoft should have found a way to credit the guy. Even just a footnote in their WinGet announcement blog post would have been better.