Earlier quoted context omitted.
Who has this access. The NSA? They didn't have this access when GitHub was independent? Says who? Backed up by which facts?
Fact is Microsoft is a hostile company and will have access to private repositories.
Look, I hated Microsoft in the '90s and '00s. I was there. I grew up in a world where IBM dominated the market though. They've both changed. The market has changed and both of these companies had to deal with that.
The reality is that nowadays people pay with their privacy instead of with currency for a product; they are the product. Does it matter much who owns the product (independent US company, big player like Amazon, Microsoft, Facebook, Amazon, or Apple?)