Only 2 million men in stasis? And 3 billion women? I think at a time of existential emergency, love takes a backseat to necessity and children need to be made. Even if they find some type of vaccine, he should still be fucking. And its not like he can't love the women he loves and impregnate other women as well. Like all of the dudes are a product of their situation and necessities except for MultipleScleroris-kun. Creating a vaccine is nice and all, but the world's smartest people & AI couldn't figure it out, so like take a seat let the women handle this, since they've been around the longest, instead of trying to fight the Pussy Illuminati or whatever.
But I mean its a manga so whatever. Its just like someone took a hentai plot conceit and decided it would be interesting to consider seriously. And then figured out it would be boring as fuck, so they decided to inject everybody with the nonsense.