This article is careless with physical terms. What it means to say here is that rotation (or energy) goes to whichever of the four wheels has the least grip. The torque of all the wheels is basically equal [0]. The ones that are gripping are creating linear force, but not enough to move the car. The wheel that is spinning freely has its torque going into dynamic friction and rotational acceleration. When that wheel has accelerated to as fast as possible (which happens awfully quickly because a wheel isn't that massive), the engine's rev limiter kicks in and cuts the total torque down to 4x the dynamic friction.

[0] Assuming ideal naive differentials.