We can think of one good reason for this move. By selling the vehicle at a lower MSRP, it has a better chance of qualifying for federal tax credits. Thus, a customer would not have to choose between having the features they want and scoring a substantial discount.
Another reason is that this streamlines production as all cars can be built the same with identical hardware, which reduces the automaker’s carbon footprint. BMW made a similar argument, and it makes a certain amount of sense.
This would also explain why the Model Y Standard Range has a software-locked battery capacity; with one production line building two cars, Tesla can save immensely. For the record, Tesla has, in the past, locked range and other features like ambient lighting and heated seats behind paywalls.