After reading this article, I can see where Facebook is coming from when making these licensing changes. However, the points he makes about smaller companies feeling pain from Facebook due to patent infringement is very real too.
And if they're feeling the pain, have any of them sued Facebook and won? If not: Is it because they're using React? If not: How does the patent grant make a difference then?
You can sue Facebook for infringing a patent with Oculus and they'll come after you for your use of React/GraphQL/etc.