See, the Founders were indeed born when the United States did not exist, and were grandfathered in as NBCs on the basis of their prior jus soli residence in the colonies.
None of which has a single thing to do with Ted Cruz, who was born long after the Revolution, and who was not born on our soil at all, whether as a state or as a colony.
They were precise in their use of terms, and knew they were naturalized, collectively, by the formation of a new country. As naturalized persons, they could never be NBC, so they included a time-limited exception to the NBC rule.
They themselves realized they were NOT Americans by birth, and had to carve out a Constitutional exemption for themselves as a result. Nothing changes that.