Yes, this. I have deliberately put non-7p people into stories because I said, "Wow, whole bunch of limited universe here. Maybe I want to think about this."
And I found that once I started doing it deliberately, various non-7p people started walking onto the page without my thinking about it. (I am of the "characters have some autonomy" school of writers.) And some of them were indistinguishable from 7-p people except in physical description, and others brought more complications with them
But seriously, getting to write about people who don't all look alike and don't all have the same ideas makes for a lot more fun writing, IMO.