Oh wow I didn’t realize they did custom licensing (presumably for a good chunk of change). Good to know!
It trips people up: the commercial x264/x265 license provides alternate use terms on the implementation. The implementation, however, is still protected by various patents worldwide and MPEG-LA is who you go through for access to the patent pool which is (supposed to) include payment to all of the identified patent holders.
H.264 is fine as it is literally the MP3 of Video. H.265 is a lot more complicated.
[0] Slide 10, bullet one https://www.mpegla.com/wp-content/uploads/avcweb.pdf