Imagine this pre fight test didn't happen.
Imagine if The Reem walks into that cage on May 26th and is staring at JDS.
The bell rings...Reem comes out and beats up JDS. We have a new HW champion....
Now imagine Reem fails his post fight drug test. It would be devastating to the UFC.
In short, Kizer (for once) demonstrated good judgement in testing these fighters at the press conference. Just like with Chael and Anderson, the UFC dodged a bullet in a sense. Yes, the #1 contenders have failed drug tests...but at least they weren't champions when it happened.
*I know it's unlikely that Reem's T/E ratio would be considered too high post fight as he seems to be able to...ahem...cycle it the right way, but use your imagination.*