It really isn't that interesting. Red Hat engineers do great work and have done so for years. That controversy has little to do with the engineers and everything to do with Red Hat corporate.
One has basically nothing to do with the other, but I'll humor your attempt to draw a connection and say that if I had to choose between Firefox having GPU video decoding and IBM/RH not trying to subvert the GPL, I'd choose the latter and forego video acceleration. This is to say, the former does not make up for the latter even if I humor the existence of a connection.
Besides, I'm still going to play videos in mpv anyway. In-browser players suck for various other reasons besides the acceleration/performance issue. The bare-bones vanilla in-browser player has virtually no features and controls cannot easily be remapped. Firefox's floating video player feature is a nice step in the right direction, but only a tiny step. Furthermore the video controls implemented by websites like youtube are even worse and fixing that on a per-site basis would be a huge chore. I'll give you a specific example: my laptop's universal volume keys are my F1, F2, and F3 keys and they're right next to my 1, 2, and 3 keys. In the control scheme youtube has implemented, if I ever miss my volume keys I jump the video back to 1:00, 2:00 or 3:00 because youtube for whatever reason thinks number keys should be shortcuts to seek to that minute mark. I guess some people probably like this but I certainly do not. I could try to fix this by injecting scripts into the youtube page, but that's a hassle I can simply avoid in the first place by using a video player that has mostly sane defaults and makes configuration straight forward besides. I'd rather configure mpv once then play wack-a-mole fixing numerous websites and keeping those fixes up-to-date and working.