My baggage tag show Class: F when I fly J class from HKG-KHH and my bag was the first to arrived when I fly KA432 few days ago......
However, I think those First Class red tag is useless at new system. I always fly intra-Asia J class. Before the new system, I remember 6-7/10 times my bag is the first arrive with all red tag. But since the new system, I flown more than 15 times with CX/KA, if the flight has no First Class cabin, my baggage tag will print Class: J, and my bags will usually come out between some blue or red tags.