Honestly, even then, the WBC wouldn't give a ****, it would just bring a little bit of unwanted attention for a little while. Hypothetically though, if there was a ring fatality or serious injury in a fight allowed to go ahead after a positive test, surely the organisers could be prosecuted?
Valdez should be banned for at least 6 months. The WBC is protecting Mexican fighters who cheat, basically bending over backwards to make sure they get the white glove service. With this move, the WBC lost every bit of credibility they had.
Canelo got suspended for sixth months. Now, one might infer that it was a meaningless one as it coincided with a surgery Canelo underwent plus recovery time if memory serves. But he still got an official suspension.