Because you stated "They are all natural-born American citizens." And that's not necessarily true unless of course you know the backgrounds on each and every one of them.
Which is why I asked that question.
Puerto Ricans are automatically U.S. citizens."
But not all U.S. "citizens" are "natural born Citizens", regardless of location. There is a distinction.
What I wrote was practically a tautology, i.e. true by definition.
If they are actually Puerto Ricans, they are actually U.S. citizens.