Exceptional sub for expelled player

[Scrapper1]

I just learned today that in USAV rules, a player who is expelled from the remainder of a set can be replaced by exceptional substitution if necessary to keep 6 players on the court.

Until now, I had thought this wasn't allowed. Maybe I'm thinking of DQ'd players? Am I right to think that if a player is DQ'd and his/her team does not have a legal substitute, then the team is declared incomplete and the set (or match) is forfeited?

So, first question is: is that true for USAV rules? But then: is it also true for NCAA and NFHS? I feel REALLY confident that it's true for NCAA, but. . .