I think this deserves a reminder that Facebook cancels all of your licenses to all of their software (which includes such things as React) if you are in any sort of patent dispute with them (whether they've filed it against you or you against them).
(Further devolving into off-topic:) What I don't understand is why they moved from BSD+Patents to MIT, and not to pure BSD, by just removing the Patents file, which would be the obvious step?
Before the relicensing it even covered things like you suing them for violating a non-software patent resulting in getting your react patent license pulled (can't remember if it was general react license pulled or just the patent grant, I think the latter).
