Oh you just made it all up didn’t you?
And here are the pre sundering maps of relevance one before night elfs existed and one after.
Before
After.
So ya while Azshara didn’t let the night elfs expan into hyjal it self it was still apart of there empire and elfs would commune with the wild gods there.
- - - Updated - - -
It wouldn’t be an issue I’m just wondering where any of the lore came from As I don’t remember ever hearing of it.
As far as some dark trolls living there it would be possible but I believe it says in chronicles they all migrated away from the area and then became night elfs though I don’t feel like checking at the moment so take that with a Grain of salt.