This technology goes way beyond that. I don't see why we should dismiss the many valid ethics questions because it is something that some gay people want. That may be a slight positive to weigh against all the other questions.
I don't think "but yeah what if you steal rich people cells and make a baby and then totally blackmail them" is quite the ethical quandary some people seem to think it is, however. It's clear to whom this is a purely navel-gazing academic exercise, and to whom this offers life-changing possibilities.
Seems like you're trying to go for a bit of a motte and bailey argument here. The issue you raise is valid, but it isn't the one being raised in the other comments, which is making celebrity babies for the purposes of blackmail, and it isn't the one my comment was aimed at.
It's rare that this happens, but the law should have a provision for this case before this technology can be used without repercussions. Not only because of the question of "who's the father" but also because of laws forcing biological parents to pay child support, for example, regardless of how the child came to be.