gonf :
Not too sure if the this is real information. But from the info I read so far. All ryzen are from "1800x" just some were tested and didn't perform as well so they got downgrade to 1700x or 1700.
Nobody makes chips specifically for one speed bin. Intel uses the same die for Pentiums and i3, i5,i7 and Xeons for LGA115x sockets, i7 and Xeons for LGA2011, etc. That's what is called 'binning' : the best dies go to the highest margin product lines, the slightly worse ones get sold one grade lower, the salvageable defects and excess production get parts disabled and sold off a whole tier lower.
Ryzen's CCX building block comes in four cores increment and Ryzen 6C12T will be using the same die as 1700/1700X/1800X, just with one core per CCX disabled, be it due to defects, not meeting specs or no reason other than to sink excess inventory.