Depends if 1st fight is ruled NC, I think WBA might do so (for the right fee of course) but doubt IBF will, they will probably give it to their man Zab for the umpteenth time in a easy title fight.
He didn't test positive for it before the 1st fight, admitted to it during testing for 2nd fight - Mosley Oscar situation, although Mosley admitted to it, didn't test positive - wasn't ruled an NC.
On B/Scene it says..."According to Kizer, the testosterone pellets were taken prior to Petersons first fight with Khan, which took place on December 10th in Washington, DC.* Apparently,* Peterson did not remember taking the pellets until his B sample came back positive."
I agree with you, but no test from the 1st fight picked that up, no one would no about that unless team peterson confessed, similar to how Mosley confessed, but in this case unlike the Mosley case, the 2nd fights testing procedure picked it up.