I am curious about the binning factor too since in the past, AMD and Intel have both made use of defect binning to still sell usable chips by disabling cores. Perhaps Apple is able to do the same with their SoCs? It's not likely to be as granular as Nvidia who can disable much smaller areas of the silicon for each of their cores. On the other hand, the specifics of the silicon and the layout of the individual cores, not to mention the spread of defects over the die might mitigate that advantage.

They do bin their chips. Across the range (A- and M-series) they have the same chip with fewer / disabled cpu and gpu cores. You pray a premium for ones with more cores. Unsure about the chip frequencies - Apple doesn’t disclose those openly from what I know.