"Facebook, Inc. ("Facebook") hereby grants to each recipient of the Software ("you") a perpetual, worldwide, royalty-free, non-exclusive, irrevocable (subject to the termination provision below) license under any Necessary Claims, to make, have made, use, sell, offer to sell, import, and otherwise transfer the Software...The license granted hereunder will terminate, automatically and without notice..."

The PATENTS file affects more than just React. It's found in their other projects too.