My theory goes something like this. The Uzumaki clan initially worshipped Kaguya when she was benevolent and known as the rabbit goddess. Two possibilities
1. She was an Uzumaki and she got the Byakugan from eating the fruit. The Sharingan then got transferred down the SO6P's line and the Byakugan down his brothers line
2. Some other connection such that the Uzumaki are related to the Senju in some way
However what happened when she was corrupted by her power? SO6P hasn't mentioned how she was stopped. She was basically a god, surely she didn't just die of old age. The only way to stop her would have been to seal her some how. What clan is known for seals? The Uzumaki.
So the Uzumaki worshipped her as a god, then feared her as a demon. They stopped her by sealing her somehow which made her into the death reaper. Then maybe as a form of respect to their former "rabbit goddess" they continued to worship the former her, which is why they worshiped that mask representing her in the uzumaki clan place.
1. She was an Uzumaki and she got the Byakugan from eating the fruit. The Sharingan then got transferred down the SO6P's line and the Byakugan down his brothers line
2. Some other connection such that the Uzumaki are related to the Senju in some way
However what happened when she was corrupted by her power? SO6P hasn't mentioned how she was stopped. She was basically a god, surely she didn't just die of old age. The only way to stop her would have been to seal her some how. What clan is known for seals? The Uzumaki.
So the Uzumaki worshipped her as a god, then feared her as a demon. They stopped her by sealing her somehow which made her into the death reaper. Then maybe as a form of respect to their former "rabbit goddess" they continued to worship the former her, which is why they worshiped that mask representing her in the uzumaki clan place.