In the 2022 order guide dated 3-15-21, page 16 in the Engine/Transmission area, Exhaust Brake is listed in the description for the 6.7 PowerStroke. It does mention the modes of use though.
The exhaust brake is also listed in the same area of the 2023 order guide (dated 10-25-22), page 18, and is listed for both the 6.7 and 6.7 HO. Again, no mention of modes of use though.
I also have a 2023 on order, and this will be my first diesel, so I've been researching this as well. From reading on the web, the Exhaust Brake "On" mode, will apply the exhaust brake whenever you let off the throttle pedal. The "Auto" mode (2 button presses), will attempt to hold the truck at the speed at which you let off the throttle. So for example, if you are approaching a long descent and know what speed you want to be at, slow to that speed, press the EB button twice (for Auto mode) and then let off the throttle.
I also saw that the Exhaust Brake will not work if the motor is at or under 1300 rpm. Above 1300 rpm, the brake will provide varying degrees of assistance. The higher the rpm the greater "slowing" (I won't say stopping) power it will have.
I'll be looking to try this out once I get the new truck. This information is from the 2022's, so I am assuming that the 2023's will be the same.
Scott