I’m not a researcher. Do a search for bushpilot1 and rxsid and read their research. They’ve proven without a doubt the original meaning and intent of NBC. I’ve read up, you can too. Your quote relates to citizenship only, not natural born citizenship.
Just do a search on their names, there are quite a few very long threads filled with references and sources and they prove their case excellently.
Mama Texan’s citations are accurate. The term NBC is originally based on the following the citizenship of the father.