You might want to look up the definition of sacrifice if you think it's synonymous with self-indulgent. It's literally the opposite.
It's orthogonal to self indulgence; what defines that is the effect. And it's inherently subjective. I'd argue most religious animal sacrifices are self indulgent. Obviously, the believers think otherwise. (Nobody asks the animal.)
In this case, they absolutely made a sacrifice. But the main effect is the fact that they sacrificed something. The sacrifice didn't actually do anything. Contrast that with e.g. putting yourself at risk to save somebody. That is more than performative.
I mean yes, we're all talking about it. I forgot what the protesters at Google who locked themselves into offices were specifically protesting, but everyone I know at Google talked about that, too. (Huh, it was also Israel [1].) This sort of outburst has basically never been an effective form of protest.
[1] https://www.cnbc.com/2024/04/18/google-terminates-28-employe...