Yes, batteries do not like to live at the extremes of their range. Since Ford is providing a warranty on the battery they are within their rights to protect the battery by locking out part of the capacity. If, after experience they decide they can unlock part of the reserve without hurting battery life, that is not extortion.
They are up front about it, telling you exactly why they are doing it and how much is in reserve. When they have more data, they may reduce the buffer.
Just as I wouldn’t mind a reasonable purchase cost for a Sentry-mode equivalent, I Personally don’t have an issue with the two levels of ADAS offered as options. You are buying optional software functionality which you don’t actually need to drive the car. Unlike the battery and motor capacity, which is integral to the vehicle.You can also buy the Full Self Driving option for $8,000, or the Enhanced Autopilot for $4,000 (this month), both are just over the air software upgrades, the hardware is already in the car.