This is basically true. You need to have certain DNS configurations you cannot afford on Tor hidden services to federate, and while you still could be listening on a Tor hidden service, clearnet servers would still need to reach you to federate.

On top of that, even if you somehow manage to do that, either youre federation trafic goes through Tor (lmao how to DDoS Tor in 1 step), or It doesn’t and all servers can see your public IP, which deafeats the purpose.