"when using the normal door button, a Tesla's windows lower slightly to equalize the air pressure"

Not correct - the real reason is because the Tesla windows are frameless and it is not possible to open or close the door without the window colliding with the gasket as it swings into place. The soft open button tells the window to retract by a sight amount allowing the window enough clearance to prevent it from colliding with the gasket. If the door is emergency opened it takes a bit of the gasket with it. Normal cars have a frame around the window so the gasket is always with the window which can only move up and down, but the Tesla has the possibility of the window rotating sideways in addition to up and down.