I get a kick out of people saying that people who paid for FSD shouldn't have to pay for HW3 as part of MCU2, but that it makes sense that those without FSD should. Since October 2016, Tesla has advertised "All Tesla cars come with the hardware needed for full self driving." No customer should ever have to pay for HW3 in any way. Now, Tesla can chose to not upgrade it until your car needs it (paid/subscribed to FSD), but just because they force it in with another update doesn't mean they can charge. They are very close to exposing the fact that not all cars did in fact have HW needed for FSD, and defining the value of that deficiency.
I see the fact that Tesla is charging *all* cars that originally had HW2/2.5 as protection against looking like they are charging for HW3. There were no HW3/MCU1 cars, so they don't need to cover pricing for that, which makes some lawyer inside Tesla very happy. They can just say that upgrading an AP1 car is easier than AP2, and as long as there is a single extra cable they need to run that exists in an AP2 car vs AP1, they have justification there.
It's a really fine line to walk, and super crappy customer experience, and it's transparent what they are doing while being legally "ok", but what's new for Tesla?
I scheduled my MCU2 upgrade early March, for an early April appointment. Will be interesting to see what they try to charge me. Doesn't really matter as I'm going to take Tesla to small claims court for the MCU2 upgrade price- they sold me a car with working voice commands, turn signal noises, and screens that don't need to be rebooted every 5th drive, and they are unable to fix that without an MCU2 upgrade, and my car is still under warranty, so it should be no cost.