Doping

Would the threshold have been adapted after TUE was no longer required?

The threshold was introduced alongside the general permission to use the stated doses without a TUE. Before that, you either didn't have a TUE and the "threshold" was the lower detection limit of the test, or you did have a TUE and presumably there was some guidance for the labs about what excretion rate was consistent with the dosage specified on the individual TUE, e.g. mine said 1200µg per day, so if they were using the same pharmacokinetic model as they used to set the threshold, then I'd have been under investigation for overdosing with an excretion rate of only 750ng/ml.