I think it never will be support 19 normal gpus.
Amd have never said that.
You have to combine it with p106 or p104 which normal people cant buy.
Ok, but the question is, i can have 11 normal nvidia gpu and 8 p106 or not???
Dont seem so. Seems u can have 11 amd and 8 p106 with the latest amd drivers.