Exactly this; no one is sorry, they're sorry they got caught after the fact. This is simply an attempt at ass covering and shifting blame onto Cambridge Analytica so users / investors / governments don't sue Facebook.
Yet, maybe it serves a purpose? It doesn't matter how sorry they actually feel, nobody is going to feel better from a large, public, self-flagellating apology. Nobody is going to be happier or more mollified or satisfied. All it's going to accomplish is to provide grist for the lawsuit mill - after all, why apologize if you're not guilty?
Again, you're completely right. They're clearly not sorry.