This statement has a number of issues. First, you have to trust Apple that the indicator _really_ can't be disabled. You also have to trust that there isn't a vulnerability Apple is not aware about that could allow rolling the camera without the light coming on. This has happened in the past [0] and there are known Apple products that are vulnerable, yet the statement never mentions this making you believe it's impos…
(1) With a mechanical shutter, the state of blocking can be trivially and reliably inspected. With electrical control, this is not the case.
(2) A mechanical shutter works by making it physically impossible for the camera to see anything, while powered or not. With any electrical control, this is nit the case.
So, either you use a mechanical shutter, or all bets are off.