Though I do think it would be brilliant to touch upon this, do you really think they would do it? I think it has awesome story possibilities but I just don't think RTD would rewrite one of his biggest characters like that. They will probably find a way around it so that whatever the result is, it doesnt affect Jack.
Also, if nobody can die, does this mean we can kill off PC Andy Gobshite? Or even better, perhaps someone can take a chainsaw to him and we can have ten hours of watching him in pain