FSR is open source
Apple MetalFX upscale technology, as it turns out, is based on AMD developments.
Apple documents revealed details about MetalFX, according to which the technology is based on AMD FSR. The latter is open source technology, so Apple likely doesn't pay AMD anything. But under the terms of the license, Apple must confirm the use of this product in its software. Such information can be found in the Legal & Regulatory.
MetalFX itself is not open source, that is, apparently, Apple modified the AMD product for its needs. Perhaps quite noticeably.
By the way, there are many games that have already been released for Apple devices or are about to be released, and these are Death Stranding, No Man's Sky, Resident Evil Village, Myst, Resident Evil 4, Assassin's s Creed Mirage, Lies of P, Baldur's Gate 3 and The Medium, including support for AMD FSR.
It is possible that in the foreseeable future the fact that MetalFX — this is actually FSR, will help the latter to expand more actively.