Intel almost never keeps a board layout more than two generations not sure why anyone would have thought they would change and keep coffee lake on the z series.
This one's hard to argue, because Z170 and Z270 (along with the PCH variants) switch came at roughly the same period as the switch from tick-tock to PAO. It used to be that prior platforms could sit two generations of CPUs (Z170 boards could sit a KBL CPU after a BIOS update as well), but now they out Z270 (with some feature upgrades) and then Z370 (i'm assuming). The pinout is probably different on CFL, but the question on some people's minds is having going to a two-step generation to a 3-step one, would the boards last 2 or 3 generations now? Or even just one?
I'm not surprised or anything with my previous image reply by the way, just pointing it out that CFL wouldn't work on 200-series boards. Kinda curious if it's because intel is bringing the Thunderbolt 3 controller to the CPU.