My guess is pirated material.
Distribution of User Content may be subject to third-party rights. You agree that by using the Plex Solution you will not upload, post, display, or transmit any of the following:
anything which defames, harasses, threatens, offends, or in any way violates or infringes on the rights (including, without limitation, patents, copyrights, or trademark rights) of others;
I'm assuming that benefit of hosting Plex somewhere is that it scales to multiple users better when running/selling Plex as a paid service and this is too visible for their plausible deniability.
It does though doesn't it, it has a fall back execution route on non-intel GPUs that isn't as good?