When Dee Reynolds and Mac put on the outfits that Mac picked out for their duties as quasi-Guardian Angels, Sweet Dee thought he looked more like Rerun than Curtis Sliwa.
For us at home, this was an allusion to the character from 'What's Happening' and 'What's Happening Now!'. But within the context of the scene, Dee's reference could have gone either way - she might have meant Frederick "Rerun" Stubbs, or the actor who played him, Fred Rerun Berry. (Fred Rerun Berry legally changed his middle name to Rerun.)
TV actors are known in Toobworld just as much as their characters, but usually we consider them to be famous for something else entirely in order to preserve the divide between character and actor.
For instance, thanks to 'The Larry Sanders Show', Peter Falk is just as much a citizen of Toobworld as Lt. Columbo, Daniel J. O'Brien, and the Latin American dictator he portrayed in an episode of 'The Twilight Zone'. So when Falk appeared on Sanders' talk show, he couldn't be there to promote 'Columbo'; he would have had to have been there to plug a movie appearance, real or fictional.
Fred Rerun Berry had enough TV appearances as himself to qualify as a character in Toobworld (and for membership in the TV Crossover Hall of Fame). He was seen backstage in a weird green room bacchanaalia (but I can't remember what show it was!), and he was famous enough to "star" in one of JD's daydreams in an episode of 'Scrubs'. His televersion also showed up in episodes of 'Martin' and 'Linc's'.
Perhaps he made his name in show business by being a "Rerun" Stubbs impersonator. In several episodes of both 'What's Happening' series, Rerun's quest for stardom was well-documented. And o'bviously he finally made it to the Big Time - as evidenced by his appearance on a variety program hosted by the guy who used to be Johnny Bravo and his Brady siblings. ("Rerun" Stubbs definitely qualifies for the Hall of Fame.)
So whether you go with her reference being about either Fred Rerun Berry or Fred "Rerun" Stubbs, the Zonks don't apply.