I wonder if that will contribute to a reversion to cults of personality. E.g., the anti-crypto relay blocking posts from accounts subscribed to the Monero relay, and so on.

Not sure, i could envision the woke relays blocking free speech relays and even bitcoin maxi relays blocking monero or other coin relays. I still don't see how relay level blocking won't result in a bifurcation like we have with fediblock instances and free speech instances on fedi