The sanctions are still there and the US will never allow them to be lifted, but this is just yet another step along the way to making said sanctions effectively meaningless. Russia has been trading extensively with the DPRK again for a while now and while they are careful to not outright violate UN imposed sanctions which are binding according to international law, they have pretty much managed to find alternative ways of doing the same thing just without strictly speaking going against the letter of the sanctions. And since Russia will not allow the US to strongarm the UN into imposing any additional sanctions to shut the alternatives down, these sorts of loopholes are just going to get bigger and more numerous until the existing sanctions are all but irrelevant.

I guess the way I understand it is that while the sanctions are still there without monitors they have a bit more room to maneuver.