(Which is to say, with more generality: people who get acquihired are basically temporarily invulnerable to office politics.)
- 'OldTubers' vs. the new Googlers is a clear us v. them thing. Bad for culture, especially when you get privileges on top. - Their plan was actually successful so there must have been a thing or two to learn on the product side, even if it's as simple as accepting engineering input and understanding the difficulty of maintaining stuff (as opposed to relying on the analytics). - There's some good thinking and ingenuity in there, despite the methodology.
I'd want to keep hold of that talent while dealing with burgeoning elitism. Up to them to quit if they don't like the changes. Fire them if their contribution begins to suffer.
Formal warning, perhaps, if it actually contravenes a written policy, but in this case is unlikely to have been one. There was no actual financial or reputation loss to the company.
THB, meh.
Although... the number of people involved in the "OldTubers" backdoor seems to have been pretty substantial, I don't know if they could really have fired all of them...
But who is anyone to say if doing anything is "right"? We're all equally qualified to have a moral compass.