I listened to an interview with him once. He used to be annoyed by it, but after having it explained to him (by his daughter, IIRC) he decided it was ok because it wasn’t really about him; his song just happened to be the bit of 80s pop culture that got used in a prank that became very popular. I think the fact that the song isn’t bad is part of what makes the prank fun rather than malicious.
There is absolutely no scenario in which everyone stops having children. If everyone who could be convinced not to have children is convinced, there will still be plenty of human beings.