It's still all speculation, because (if I'm not mistaken) we don't know for a fact that these (Vega FE) results are from gaming drivers.
But yes, it does seem to be a fact that gaming drivers score significantly worse...
AMD would be killing their chances in the Professional Workstation field before Vega is even out if those Frontier Edition results were running Radeon Pro drivers; and couldn't even handily beat a card with less than 50% the TFLOPS, that's 50% cheaper from their own line up.