If there is no evidence that testosterone serves to enhance athletic performance and recovery, then it should be immediately removed from the banned substance list. If I was someone who had been punished for unacceptable testosterone levels I would proceed with an appeal to the Court of Arbitration and use this case as a precedent.
An Indian intersex sprinter, Dutee Chand, challenged the IAAF's requirement that such athletes undergo chemical treatment to reduce their levels of performance enhancing testosterone. Her case reached the CAS (Court of Arbitration in Sport.) Unbelievably, they ruled there was no scientific proof that testosterone is a performance enhancer. The CAS suspended the IAAF's treatment requirement, giving the IAAF 2 years to return with "proof" (which Semenya is currently supplying in spades, by destroying (and ripping off) actual female competitors.
The arrogance/incompetence of the CAS is stunning. They issued a ruling that immediately invalidated itself and destabilized a sport, in the process deposing and discarding with present champions who achieved their status through years of hard work and by following the rules. The psychological impact of that on the 800's fastest runners (Wilson hasn't run a 2:03 since probably high school) has to be intense.
If the CAS sits back (in its quaint chateau in Lausanne) and does not the remedy the injustice it has inflicted (which seems likely) then the athletes themselves should protest, because they are getting hosed.