I agree with your points about sex workers and speech about sex in general, but your comments about people in autocratic regimes ring a little hyperbolic. Chinese [1] users were able to use Signal until the Chinese state seemed to block it at the network layer. WhatsApp is blocked too. That's unfortunate, but what's Apple got to do with it? And what exactly could they do to prevent it that the state wouldn't get in the way of?

[1] I'm assuming that "autocratic" here refers to China - though despite the lack of political freedom and the awful situation with regard to ethnic minorities, I don't think that's a very helpful or expressive label.