I have no idea but another case is RakNet (another Facebook property, via Occulus). It even uses the older, more controversial wording: https://github.com/facebookarchive/RakNet/blob/master/PATENT...

And I'd find it highly unlikely it contains any patents too. Occulus was bought in March 2014 by Facebook and RakNet was bought in April 2014 by Occulus and there is only a handful of commits on GitHub that don't seem substantial at all and are just maintenance and cleaning up the repo. RakNet operated for years before that so it's unlikely they happen to have had a patent in it at the time of its purchase or they'd be nuked by Facebook before.

Then again, there are/were patents for some bit tricks and Carmack's Reverse so anything is possible.