Elon Musk is very likely a supporter of eugenics and since he's also a narcissist who thinks he's better than everyone else, it makes sense that he's obsessed with spreading his genes.
Just remember to conveniently ignore actually raising those kids, and those who happen to not fit his mold of what a person should be like (e.g. if they happen to be trans or see through a modicum of his bullshit)
She definitely isn't going to consent to being impregnated by Elon so the only conclusion is that he will rape her to get her pregnant. Whether he intended to threaten her with rape or not, he is threatening her with rape.
Maybe he's misunderstood. Maybe another one of his children doesn't agree with him and he wants to get rid of it. He'll take the cat in exchange. A somewhat understandable offer.