Your evidence of a general Muslim crackdown is exterior cosmetic changes to some mosques which were cherry-picked by western media?

State Atheism is a CCP classic.

why do all the Mosques suddenly look like Han temples?

So atheist China is making religious temples look like other religious temples? Pick a lane.

I think that this theory comes from the West’s Han supremacy narrative (projection, much?). But again, even NATOpedia has counterexamples: https://en.wikipedia.org/wiki/Affirmative_action_in_China.