I don't think shared hosting is very common with tor hidden services, especially sharing the same hidden service address. There are probably examples of it, but

I don't think shared hosting is very common with tor hidden services, especially sharing the same hidden service address. There are probably examples of it, but they're rare. A likely use of hidden-service-deanonymisation is finding the server that runs a drug market (silk road-style). Those are overwhelmingly likely to be on their own server. Another commenter already linked to the tor project's response, which suggests that this kind of website profiling attack is less accurate in the real world than their introduction would suggest.