The whole issue with HEVC is the fragmented licensing situation and the lawsuit risk it entails. This is why the largest, and therefore most vulnerable provider, Google/YouTube, won't touch it. This is fundamentally different than previous generations: streaming companies don't want to drop it because there's something technically better available, but rather streaming companies want to drop it so they don't get sued, and if they do, the damages are less.
Oh please, this is the exact opposite of the actual problem.
When the MPEG-4 group got together on a successor to MPEG-2, there were two objectives....the technical ones and the legal ones. For the legal ones, everyone knew all of the patent holders. They were pretty much the same entities since MPEG-2. But most companies just don't cede their IP for free so they had to come up with a patent pool system that would reward IP holders depending on the relevance of their work in the final standard. All this took years to negotiate just to get MPEG-4 done.
Meanwhile Google had purchased the company behind VP8 which claimed to have a competing standard that was "patent unemcumbered". The problem is just because you claim that doesn't mean it's true. And by the time that VP8 was a thing, MPEG-4 was already in place in phones, computer graphics chips, professional workflow applications, satellites, you name it.
So when it was time for to replace MPEG-4 with what became HEVC, the standards body took a similar approach to what had been done with MPEG-4. All of the IP holders get together for a patent pool approach which means that IP holders would get paid from professional entities. And it would make it much less likely for member companies to get sued by trolls. This is especially important to a company like Apple. Patent trolls and trial lawyers see their $250m war chest as money for the taking. I'd be curious as to what Apple's yearly budget numbers are for expected patent trolls they end up buying off, regardless of the merits of the case.
But Google decided to keep going on the VP strategy, this time introducing VP9 and saying again that it was patent unemcumbered. And again, it's not claims that have been widely tested in court. And yes, Youtube would be one of the world's largest payees into the Mpeg-4/HEVC patent pool. It's how it's supposed to work. But from where I sit, I think Google is continued with VP9 for two reasons. First, that it might be cheaper to do VP9 at Youtube and just quietly buy off IP holders if they ever got challenged. And second, a power struggle between Apple and themselves for supremacy on a ubiquitous technology everyone uses everyday.
So now we have AV1 and again, we have the same arguments about being unemcumbered by patents. The difference here is that Apple seems to be a part of this consortium now. It's unclear why but there could be multiple reasons. First, it may be that Apple likes Google's strategy, regardless of the potential legal exposure. It could be that the Apple TV strategy of expanding outside of Apple hardware means that Apple may have to participate in the AV1 sandbox to be a player (especially on devices running Android). Or it might be that in order to limit Google's influence on a key technology that Apple sees being in the room as the better strategy.