As sad as it is, I can't see Nine ever REALLY wanting a gay relationship on BB. I'm sure they would be okay with it, but I can't see them pushing for it. The entire show seems to revolve around straight romances because that appeals to the tweens. I'm not sure that, as a country, we're in a place where they think a gay relationship would be the best thing for their target audience.
The gay novelty as it is for the current day BB is "Yay, let's all laugh at the flamboyant gay man!" It's one of the worst parts of the live shows. You can guarantee they'll get Jason to do something and the audience will laugh at it.