China is kinda irrelevant here because western social networks and services are blocked there anyway, so the Chinese government can indeed compel Chinese companies to spam users with political propaganda (and does), but western companies are irrelevant in that process.
For Google and PRISM, I'm sure it won't change your mind, but I worked there at the time and the reaction was genuine. If there were people inside the firm who knew about it at all it must have been a very small group of spies/double agents, and such people were never detected despite a thorough search. Given that it was all based on fiber taps done by telcos though, it's not clear why they'd need any insiders. The assumption of formal cooperation was based on the phrasing of one or two sentences in some leaked documents, but the way the whole thing was set up didn't actually require it so, what those insiders would have been doing was a bit unclear.
Anyway, this is all by the by. We can't know what will happen in future. But if they won't budge on E2E encryption then it seems unlikely they'd be willing to bypass anti-spam measures, which is far more detectable, far less justifiable, and probably doesn't fit within any existing laws.