drop or are they rng and be random generated stats

The vast majority of raid gear will continue to to have pre-determined secondary stats, just as it does today. We wow gold may still put in a few alternative pieces with randomly-generated stats, much like we did in Throne of Thunder, but those will be rare exceptions.

This extends to other types of content as well. Every once in a while, when there's a compelling reason to, we might let gear randomly roll secondaries. Timeless Isle is a good example of a situation in which that style of gearing makes sense. Again, that's the exception, not the rule. Under normal circumstances, secondary stats will still be pre-determined, not random.http://www.euwowgold.fr/