OP has a reasonable concern, Microsoft has had a troubling past history, and embrace extend extinguish hasn’t gone away, just look at the office file standards shenanigans.
It’s certainly the case that the purchase of github is intended to create a platform that has network effects (making it hard to leave).
Microsoft has proven many times that their participation in FOSS tends to come with a catch or an intent to subvert.
https://en.m.wikipedia.org/wiki/Embrace,_extend,_and_extinguish
OP has a reasonable concern, Microsoft has had a troubling past history, and embrace extend extinguish hasn’t gone away, just look at the office file standards shenanigans.
It’s certainly the case that the purchase of github is intended to create a platform that has network effects (making it hard to leave).
Microsoft has proven many times that their participation in FOSS tends to come with a catch or an intent to subvert.