React's license is BSD. The PATENTS file additionally ensures that Facebook grants you a license for any patents they might have on technology that's in React. This grant—not the copyright license—expires if you sue Facebook, which is pretty standard for a patent grant.
Note also this clause:
> Notwithstanding the foregoing, if Facebook or any of its subsidiaries or corporate affiliates files a lawsuit alleging patent infringement against you in the first instance, and you respond by filing a patent infringement counterclaim in that lawsuit against that party that is unrelated to the Software, the license granted hereunder will not terminate under section (i) of this paragraph due to such counterclaim.
Please don't claim that the BSD license is revoked if you sue Facebook, and please read more carefully before you make claims of that nature... because not doing so leads to FUD, and also endless confused and uninteresting threads, as has happened in so many previous React threads.