In sociological terms, he is a prophetic voice using the media to point out what's wrong with our society and alert people to "wake up."
He was invited to Georgetown by a student-run organization. One of their other speakers was the director of NORML, an organization trying to legalize marijuana.
I don't think that his comments were meant to infer that Jesus was gay. Maybe it was just to remind people that while Jesus was on earth, he dined and socialized with prostitutes, tax collectors, and other marginalized groups in his culture. He challenged the establishment.
In his prophetic works, does Moore sometimes go over the top? Of course he does. It's hard to attract the attention of people who base their decisions on deceptive campaign ads financed by big business.