I don't see it. Silva has already fought guys with wrestle heavy game plans and still won.
I think you are confusing two different things. Guys used to fight off their back more back in Silva's time - true or at least it seems true on the surface. Fighting off your back was a winning tactic during Silva's time - not true, it was a MAJOR disadvantage to fight off your back.
Silva's era if you were taken down, regardless of any damage that was done, you often lost the round. This era is actually much more balanced to properly grading the ground game in the context of an actual fight. Someone can get taken down like 3 or 4 times in today's game and still win the round because the guy who took him down didn't do anything while getting pieced up on the feet.
Just because Silva could fight off his back didn't mean he wanted to be there or that he was easy to take down. Any fighter who is incredibly fast and accurate with their strikes is not going to be easy to takedown (see Lyoto Machida blowing up wrestlers for much of his career, who also comes from that era where bigger guys had BJJ blackbelts for defensive purposes).
I think as much as people like to say that wrestling is the best or whatever, they should also acknowledge that clearly at the higher weight classes wrestling is not as useful or seen as the meta. Striking is more important in the larger weight classes, that wouldn't change if Silva fought some random Russian guy (there are already Russian middle weights with wrestling backgrounds in MMA .They don't dominate because just being a wrestler isn't enough to dominate at any weight class much less 185+ ( khabib/islam are not "wrestlers").