No, UC San Diego does not offer an MM in opera performance, nor put on operas. If you want to study opera, rather than New Music - than it is not the right place. Perhaps best to go there after further studies. If you want a performance degree, but also want a chance to sing new music - than I would suggest picking a program known for composition - as they will be more open to the music of now. The pursuit of composition simultaneously is a different question.