There are ride height sensors - leveling will mess with where the ECM thinks the shocks are in their stroke
It would be fairly dumb of Ford engineers to assume ride height is constant for all trucks all the time. Heavy aftermarket bumpers. Winches. Spring sag over time. All kinds of reasons ride height changes.
All it takes is a few lines of code to calculate a running average ride hight and use that as a baseline instead of assuming every truck will always be at the factory spec now and forever.
Common occurrence, easy fix. Hopefully Ford engineers are smarter than that.