Re: "There's a long history of API's being *outside* of the bounds of copyright"
No, that statement does not mean what you think it means. If it did, then software could not be protected at all, which would be an untenable situation.
If the original creation meets the threshold of originality then the affirmative defence raised by the maker of a derivative work fails. So all APIs are in copyright, and always have been, but not every attempt to protect it against copying will succeed - as we learned from the SCO case.
This is Google’s big lie.
I do hope this helps you, as you are really struggling here.