I just got the same warning on FF with uBlock. Both Freetube and NewPipe seem to be fine though. I guess Freetube it is until uBlock is patched.
I just checked a bunch of random videos, ff with uBlock, none of them displayed this message.
I believe they tend to roll these out in batches. It creates less uproar than hitting everyone at once.

Somebody else mentioned possible region tests, too. I can definitely see them doing these things.

I wasn’t trying to be like “well it didn’t happen to me so it’s not happening” at all. I fully expect to see it eventually. I hope not though.

Oh yeah, I didn’t take it that way, no worries.

They come and go though. Usually there’s a solution pretty fast when it happens.

There is a fix for ublock, go into the ublock provided lists and disable the quick fixes list