I don't think they will drag his death into next season. I think we will probably find out the facts next week and probably see how it went down emotionally for everyone in the finale. It's been leading up to it for a while and I think they would show it in the promo if they were going to be revealing how he died.
Honestly I bet next season will be about showing how Rebecca went from losing Jack to marrying Miguel and I'm not looking forward to that. Im definitely curious, but I also don't want to see it
.