Advice would be greatly appreciated.
Thank you for sharing, and welcome to the forum. Some people have been very direct in their advice. I'd too say RUN! However, seems like besides dating, you have a history, he seems more than just some guy you started dating. To me that makes a difference.
If you care about him as a human being, and as a friend, you might need to decided what kind of relationship, if any at all, you want to have with him. He is in cult, and as such, he might need to make certain choices himself, if he wants a relationship with you.
So I'd say RUN! from the nonsense of that organization, but keep the lines of communication open. This experience that he's having with the elders might making reconsider his relationship with that organization. If he decides to leave, he will need our support. However, leaving has to be his decision.