I'd argue it means the opposite.

In terms of Skyrim though the nords have been there for about 4,000 years.

I'd say if you're the first people there congrats you're that Natives. If you've replaced/eliminated the original population and lived there at least 1,000 years congrats you're the natives.

Honestly the timing is arbitrary, I pick 1,000 because in modern day it's nearly impossible to track back descent that far. Very very few people can. In a society like Skyrim I'd argue it's after the last person that remembers that last person that moved there. About 6 generations or so