Not sure who Fr. Z's bishop is, but I think he's based in Rome so he doesn't have to contend with the goofier American heterodox bishops, who at any rate have far less power than when Mother A locked horns with them.
Times have changed but you’re right also, Fr Z is based in Rome so liberal leaning Archbishop Flynn of Minneapolis had little control over him. I had forgotten that. Now Minneapolis has a more outspoken orthodox bishop anyway.