These guilds have publically spoken about how little split-raiding mattered this tier.
I think it was Max who went other their raiders' gear and pointed out how half of their gear came from PvP, 4 items were BoE, maybe 1 item came from the raid and the rest were random ass shitty m+ or whatever pieces (I think Roger killed Denathrius with a 203 weapon or some shit like that). Like, fuck, you get get a 233 weapon from PvP the week mythic Nathria opened iirc, which is just flat out retarded.
The biggest offender this tier were 4 fucking stupid BoEs for every armor type and PvP being a targetable item source while both raiding and m+got nerfed into oblivion in terms of drop chances. And I'm pretty sure that what blizzard is going to take away from this is that the PvP vendor was a mistake and that they drag PvP gearing down to the pathetic, disappointing and frustrating levels of PvE.