not just microsoft but a whole heap of companies have embedded backdoors and kill switches in everything, they can easily fabricate a "cyber apocalypse" any time they want to
this is part of the reason why it's so important to understand that hiding source code is ALWAYS a red flag, no matter what, no matter what you think about market advantage, these dark places are almost always hiding something and if they aren't, someone will see the opportunity and plant something malicious in there
that's what the original easter egg was too... and the dude that did that did it in protest against the culture of the software company
maybe you don't have bad intentions but hiding your source also enables someone to piggyback on flaws you made in your code that determined hackers can exploit
so, yeah, nah... FOSS for anything that has value, or GTFO