You asked me (I don't know why) whether the law is enjoined from treating heterosexual couples who cannot have children different than those who can. I said "No."
You disagree (again I don't know why). Just because there is no such law doesn't mean that such a law would be unconstitutional. "The question is not asked of them at the time of licensing" is totally irrelevant to what the Constitution allows or doesn't allow.
Rookie mistake there, the Constitution must ENPOWER the government to do specific things. In other words, the Federal government cannot do anything that the Constitution does not specifically grants it authority to do.
In turn, State governments can only do those things specifically authorized by a State's Constitution, any powers not specifically granted to the Feds or the State, falls back on the citizens.
A State may not violate civil rights by passing a law.