It will be the adult timeline IMO. In the last 2 years the downfall, adult and pre split components have all had games released (even if one is just a remake) while the newest thing in the adult is TP from 2006
I dream for a MM Sequel/TP Prequel that ends up explaining the origins of the Hero's Shade in TP. Link is mid-late 30's and has a young son/family on the Lon Lon ranch with Malon, however, there is some big bad evil that comes along which he must take of. But, instead of the usual everyone lives...
I must be a lone ranger as I would love to see an older Link. I don't mean a teenager I mean like late 30's/early 40's possibly with a young family he must abandon in order to save the world. It would be a great change of pace and would fit a post MM pre TP setting great! (heroes regret...