No problem with this.
Get permission to exhibit.
Of course, if tribes don’t give future consent, people won’t be able to see these items and learn their history.
This happened on a local level a few years ago. A nearby band asked for and had returned several items that were on exhibit. They’ve declined to loan the items for future exhibits.
The local historical society was gracious about having them to previously exhibit, and they’ve also been fair and honest when they tell visitors that the band has declined to loan items for future exhibit.
I agree. How would any of us like seeing the bones of our ancestors just piled willy nilly on shelves in some storeroom?