There will be an American with more children then Elon Musk who is famous enough to have a Wikipedia page, and whose fame did not mainly come from their status as a parent of many children, nor from entertainment type activities (not from personally producing music, art, standup, writing, sculpture, and similar future things). If they are say a nonmusical ceo of a music production company, no problem. Athletes do not count either, if that was the origin of their fame.

The number we use on Elon's side is the highest value of "how many children did Elon have"

There must be a time from now into the future where it is true to say "This person has more children than Elon has, right now."