:agree:The first valve check is supposed to be at 6K, then every 12,000 thereafter. (No, I don't agree, but that's the maintenace schedule.) Looks like they let it slide on your 6K service. Both this and the fluid flushing procedures are labor intensive, so the service intervals that include them should cost considerably more than a simple oil change interval.
I think some are missing this and not realizing the second valve check is at 18,000 miles.