Apparently, the confusion thus arose from there being a Challenger class in the slide show and a Challenger class in the comic world, and there being a report of what shapes of ships had been seen in the slide show and a fan awareness of what "the Challenger class" ought to look like...
Exactly. That's the same confusion that led to the erroneous Rigel class description of "a Galaxy saucer and three nacelles attached to a Constitution secondary hull" (which was actually the Niagara class, but not actually those parts, just similar looking parts).