On my Golf I've enabled the tyre pressure monitoring, which isn't included as standard (or maybe even as an option) and is just software - it checks the relative rotation of each wheel rather than queried any sensor, so it's a hidden software switch to enable it.
The car is 13 years old.
I am also reminded that test equipment has done this for a long time - there are mega-threads on here on enabling paid options in scopes from the turn of the century. So having built-in but disabled options isn't new.
The difference with this BMW stuff is firstly the idea of a subscription (but we're also use to that with, for instance, satnavs), and this thing about the Tesla batteries. I think it is one thing to carry the hardware for, say, heated seats which isn't used (my bike has all the wiring and software and connectors for a radio and even the fake radio receptacles to hold the connectors in place, but no radio), and a huge weight to lug around as a penalty.
Although... if only 66% of the battery capacity is being used, doesn't that mean the battery will last a lot longer, making that actually a useful unused option?