My car is a rear wheel drive, so no, this is not an effect of all cars. Yet, if I use the brakes I brake with all four wheels, with more breaking at the front (as is evidenced by needing to change the pads more on the front).
Rear wheel drive or not, weight shifts from your car's rear wheels to its front wheels when decelerating from forward motion. Unless your car also has rear wheel steering, this is a good thing to maintain while you are going downhill.
To paraphrase Jules Winnfield, "Physics, motherfucker! Do you speak it?"