Probably because they'd be incredibly weak if applied here. I doubt they are though. They were borderline for old AMD builds. X299 would never accept them.
This is really an entry-level X299 board. That's part of why it is rated highly; for entry-level the feature set is pretty solid for the asking price.
There is critical attention being put on the VRM design for this platform because I think some certain board makers might have forgotten to read the design documents and see the basic spec for 300W. People are complaining about paste TIM and shoddy VRMs and most missed that super-important part of this platform since day one. A board MUST be capable of that power usage, FOR STOCK!!!
This isn't your kid's mainstream platform boys and girls, where everything is simply, and you love the trees and your PC only pulls 150W at load and 25W while you stalk the people around on facebook and twitter. This platform is going to kick your ass if you don't know what you are doing, and that goes for the hardware makers AND the end user.
I am loving all the "Intel sent me 7820X and I don't know why". I'm using mine right now, and I think I know why.
I mean, I could pull the board out of my system and check if it was really important, and that's why I'm asking; like is it worth my effort?