Given the revelation that quite a few famous top-notch athletes in other sports have been known to be taking banned substances under TUE, I'd say that's a good and safe option if she doesn't want to lose all her ranking points. Why risk anything when there's a safe and officially approved way. But I tend to attribute it to a compounding of reasons, one, her health issue, the way Li Yongbo and Zhao Jianhua put it, it's not injury (I suspect gynaecological problem without speculating too much as we should respect her privacy);two, her disappointment at Rio'16 without even a bronze medal, specifically let down by Yu Yang including her embarrassing outburst; and,three,her parents who might be pressurising her to finish her university studies now that she's flunked her Olympic goal (I repeat, her parents were initially strongly opposed to her going full-time professional but she insisted and I won't be surprised she struck a deal with them to let her try out for a few years to see if she could make it big,if not, she'd go back to school, something like that if I may speculate on this one. Whatever it is, somebody posted that she's got a place in Wuhan University and I supposed the new academic year begins early next year). So , all in all, she's in a quandary and needed time to recuperate and think it over during the off period which I guessed is what the CBA would've like her to do instead of retiring in a flutter. Just saying.