Which are for light/heavy use. The more severe service schedule is probably a little excessive, but it is better for the car to follow it if it is a 'keeper.'

If it is not in either schedule, it's a dealer 'pack' item that are sold through to increase service revenue and profit in an era when cars are so good, a lot of techs are standing around waiting for their next job. It might work, it might not. Modern oils and good PCV systems have pretty much negated the need for flushes, although if you look at a few "Customer States" videos you might be surprised with how bad maintenance can get when ignored.

My former go-to GM store was pretty good about not jamming me up on 'menu selling.' They did endorse a few services that produced a noticeable benefit, when we had a 'keeper' in for service. The "BG Clean" treatment for the intake system was always a good investment, cars felt like they picked up 20 horsepower and ran a lot better afteward.

A former industrial comms employer had Wynns as a client, who had a whole system to sell through fast oil change places. Wynns had a graphic description showing the before / after benefit. In fact, I have a complete system that I fished out of a dumpster that is for sale from the mid teens that covers most FI cars for sale now, never used.