Even at Christmas time, we have to pay the bills at Toobworld Central.....
Rizzuto is one of those televersions was a serlinguist, able to communicate with people in the Trueniverse. But he was also able to talk to the denizens of the Tooniverse, according to this blipvert. (He may have been using special communications technology similar to that used for Space Ghost to converse with his guests from Earth Prime-Time.)
Characters from the Tooniverse can cross over into Earth Prime-Time, so I don't think this has to be relegated to the Borderlands.