Since Wu Zeitian had already overthrow the Tang dynasty to set up her own Zhou dynasty, isn't it strange for her to pass the throne to Li Xian? Even though Li Xian and Li Dan are her sons, but they are not capable and wise people who will be able to do a good job in managing the country and letting Li Xian become the new Emperor is like overthrowing the Zhou dynasty that she just set up and restoring the Tang dynasty..
What do you think will happen if she decide to pass the throne to her newphew Wu Sansi instead so that the Zhou dynasty could be continued?