No, most OEM 4 & 6 piston calipers are direct mount, while most aftermarket 4 & 6 piston calipers are bracket/radial mounted to allow one caliper to be used with different size rotor combinations.
Whether a caliper is direct mounted or say radial mounted ie Wilwoods, doesn't confer an advantage or disadvantage one way or the other. Just a different design. Prior to 4 and 6 pot direct mount being common, pretty much everything used some sort of abutment bracket because that's what setup the sliding function in calipers with pistons on a single side. In calipers with pistons on both sides, provided the caliper is properly centered, the caliper itself doesn't move, only the pistons do.
Works out to the same from a fluid volume perspective, instead of pushing 1 piston say 5mm, you push 2 opposed pistons 2.5mm each- the pad tolerance/kickback is the same in both scenarios when your foot isn't on the brake. In the single sided, the piston is actually pulling the caliper 2.5mm across the sliders and pushing an additional 2.5 out on one side. However the big advantage to multi pots on both sides- force is a factor of fluid pressure applied over piston area. While individual pistons are smaller, the cumulative piston area is larger than single sided calipers, enabling more force to be applied to bigger pads on larger swept area rotors using the same fluid volume and system pressure.
Got a bit off track, but figured the explanation wouldn't hurt.