Board Thread:Naruto Discussions/@comment-11891028-20170719213849/@comment-734582-20170720071517

Well, we know from Jinchuriki that they die if their Biju (a spirit) gets extracted. It seems to me that the sacrifice of an ET only dies because of this. Similar to Jinchuriki, the spirit can take over the body and mold it in it's own image.

By that analogy, i would suggest that the host is alive until Rinne Tensei is cast. The main reason for this is as mentioned by others: with RT the body became Madara's fully. So it makes sense that the host passed away at that point.