I'm definitely a believer in all these different Time theories but I think that after the last episode, they've given away an answer and it therefore cannot be the answer. Does that make sense? They hint at absolutely everything and one or all of them will be right in the end. I've said it before, I think the big twist at the end won't be a big twist at all and a lot of the theories will build up to make the story come to an end. But Time won't be the only one, because now they've hinted at it and that can only mean it isn't the final answer.