Yeah that seems… broken. My rudimentary understanding was that “smart contracts” were executed by each node. But the whole system is so convoluted it’s hard to determine where the real dependencies are. If you’re saying the Tornado Cash “smart contract” stopped executing after the devs were arrested, that’s a pretty good indicator that there was some centralized server dependency. It’s sad and unjust, but not unexpected.
I looked around and someone forked the code and is updating it. Perhaps they are using it on tor? https://git.tornado.ws/tornadocontrib/tornado-cli
But it says this "List of rpc & relayers for withdrawal Refer https://chainlist.org for a full list of available public RPC URLs. Note that most of the RPC would censor sanctionded pool contracts. So either you can use the default RPC or find yourself a suitable one."