LOL, in a manner of speaking... I suppose you could say yes. Although, it is a bit more complex than that.
Opera singers, and other classically trained vocalists, are different from pop singers in many ways- but one of the most noticeable (and I think, impressive) is that we're trained to sing without any (or VERY LITTLE) amplification. That's quite a feat, considering that your accompaniment is a full orchestra in many cases.
So, many opera singers use a technique called "Singer's Formant" which brings the vocal tone out of the throat and into "the mask" (or the face). This gives the tone more... edginess, I guess you could say... to allow it to be heard more easily over the orchestra. By centering the tone in the mask, it sometimes does sound more nasal... and many singers will tell you that they feel the tone "buzzing" right around or behind their nose when they sing.
Opera singers don't sing specifically out of their nose, but the nasal passages do play an important role in allowing the performers to produce the full rich tones that the audience clamors to hear! Hope that answers your question! :)
