Has no one ever explained the birds and bees to you?
Homosexuality, by its very nature limits procreation. I don’t think that’s in question. It is one of a list of things that effectivey does that: birth control, abortion, homosexuality, and euthanasia.
I think the question you’re getting at: Are those in the pro-homo lobby (who happen to be hetero) advancing the homo agenda as a population control method? To be honest, I haven’t heard that in any of their arguments. They certainly are not shy about extolling the virtues of birth control of birth control to limit the population in the third world.
I’m sure some of them think homosexual sodomy is population-inhibiting, but it’s incidental. You sometimes have to take these people at face value. They believe this is something good and to be celebrated. Even though we understand it to be part of a wider assault on western civilization.