]No, it wouldn't, and it wouldn't have made sense, since Dana was not a virgin and her friends knew about her affair with her professor. But a man was never going to be given the role of the Virgin, whether he actually was or not, just like a man was never going to be given the role of the Whore, even if he were an actual hustler or gigolo[. And a woman was never going to be given the role of the Scholar or Athlete/Jock, even if she were the most intellectual and educate or the most athletic. The whole point is that these roles are very specifically gender-defined. Notice that none of the male stereotypes are related to sexuality, but the two female stereotypes are all about sexuality. Women must be classified either as Virgins or Whores, with all the value judgments and fetishization that goes with it. The movie's criticism of these damaging stereotypes wouldn't work if it ignored their inherent sexism.
(Spoiler Code Removed Because, Well, Thread Title and All.)
Exactly. The archetypes they "cast" didn't need to perfectly fir the role just satisfy it enough for the purposes of the ritual. The Director at the end (Sigorney Weaver) admits as much when she calls Dana "The Virgin" and gets a "Virgin? Me?!" in response. "We work with what we got."
Dana was "virginal enough" for the ritual and whatever manipulations they hard on her in the meantime satisfied the ritual needs. Curt wasn't really a jocky ass and the blonde girl really wasn't a ditzy slut. They were all being manipulated to satisfy those roles for the ritual.