Actually the 1790 law was rewritten in 1795 and it excludes the words natural born.
The law was rewritten solely to extend the amount of time resident before one could be naturalized. No discussion of natural born is recorded that I know of and is irrelevant since the original intent of the First Congress is evident in the first Naturalization Act.
There are only two types of citizens. Naturalized or natural born. That’s it.If you have not been naturalized and you are a citizen.... Well guess what?