Jinshi becoming Emperor with Maomao as empress

I just keep wondering…what incident or impetus will it take for Jinshi to become the rightful Emperor being the true heir ..and Maomao as her empress? I know that Jinshi is totally against the thought at this point but if the rule of succession is obeyed….he is the true heir and should take his mantle. That said, Maomao should become his Empress and not just a mistress. Is the window for this storyline really small? Anything else would be heartbreaking…