You're quite correct wrt the 4C vs 8C scenario, so yes there would be two clear product lines based on number of CCX. I was thinking along the lines of 8C vs. potential 6C, and 4C vs. potential budget 2C, for which there's no significant difference between a faulty chip and a deliberately degraded chip.
Agreed, there's no significant difference between a faulty chip and deliberately degraded one from the standpoint of the manufacturing process. However, typically when you contemplate a maneuver like that, you are doing it in anticipation of creating parts via an alternative process that allows you to increase your effective yield. The goal is to increase your net profitability, not reduce it. That is precisely what would happen in the case of a 6C product, which can only exist by deliberately crippling product (whether that product contains already defective items, or a surplus of otherwise good silicon). On the other hand, taking failed 8C and turning them into 4C IS an effective way of bolstering supply of a product that you are ALREADY making, just via an alternative method. This is more akin, IMO, to your analogy earlier of downclocking.
Let's look at it this way: when I manufacture a batch of AthlonXPs, all of the chips are identical in every respect. I know, based on historical yields, that some of those chips will clock very well but others will barely make the cut. I also know what I can expect to sell for each speed bin. I have no way filling the speed bins to make the manufactured yield equivalent to the desired yield, so I may have to take some higher clocking chips and sell them at lower prices, but that is understood from the outset, and the physics of the process don't allow me to do otherwise.
This is quite different from manufacturing a bunch of Ryzen 8C chips, where I have to actually cripple part of my otherwise good yield in order to make a cheaper product. Here, I DO have a way of affecting the outcome by simply changing my product configuration. In this scenario, it makes little sense to design the product such that I have to destroy good yield in order to make MOST of my product.
I suppose it might make sense if the anticipation is that the 6C CPU is a niche product with small sales figures, but I don't really see that happening. It might also make sense if chip yields are such that MOST of the 8C product is defective otherwise, but I don't really see that happening either; otherwise we end up with chip prices like Intel's 6900K.
Of course, all of my impassioned analysis is worth sod-all at the end of the day, because I'm making it with a blindfold and earmuffs. The only way this will be definitively answered is when AMD reveals the product lineup, and I'm certain I'll be wrong. The only question is "How wrong?".
