I would imagine for anyone testing positive after these ranges are in force (supposedly September or October) all past positive tests would be fair game.
I have to applaud Nevada for finally taking the PED issue seriously (other than their hard to understand heavy stance on marijuana) this is a good thing for the integrity of the sport.
I'm very interested to see how this plays out. I've mostly been in the 'I really don't give a damn' camp but do believe that there should have at least been some way for fighters to know if they were fighting an opponent using PEDs. And I actually much prefer and have much more respect for natural athletes.
I thought this had the potential to go the other direction with it being allowed to some extent and with the commissions/orgs doing some kind of oversight so there would be transparency, at least fighters could make the choice if they wanted to go into the ring with a roided out opponent or not vs going in unknowingly and risking their face.
One reason I considered that is because it's been speculated that upwards of 75-80% of the fighters are using some form of PED or another. And extensive testing would seemingly be very cost prohibitive and then if the majority of your field is getting popped, it could create quite the fiasco.
And with these new stringent guidelines, I guess we will see if that scenario plays out. I also think just as with other things, the technology/science around PEDs seems to be one step ahead of that of the testing side of the house. Where there's a will, there's a way.