Not all of them are landed in CURRENT yet, much less stable/12. They'll be in 13.0; I can't speak to any future stable 12.2. On the other hand, CURRENT is pretty solid. A lot of folks, Netflix included, just run CURRENT.
Sure, they might run into some bug in -CURRENT, but what's the chance of a bunch of their OCAs all hitting it at the same time?
[1] https://www.youtube.com/watch?v=vcyQBup-Gto (about the 12 minute mark)