That said, Y-up fares like this are really common on Delta and SkyTeam partner airlines; I know I’ve booked at least one AeroMexico trip with a Q fare basis that booked and credited as I class flights. Delta themselves also often offers Y-up fares that credit as the effective business fare, not the underlying coach one. I can’t say I have much KE experience because the relationship with DL is so new, but I suspect these flights will credit correctly as C for all segments except the JFK-ATL-JFK ones that book into E.