Wilwood's version. I believe they do it so they can make one rotor, and then different hats with different lug holes and "off set/back spacing" for different vehicles (to line rotor up with center line of caliper)
Wilwood produces over 120 different rotor styles and diameters for street, racing and other high performance applications in standard, slotted and drilled and slotted styles. Rotors are made of steel and carbon ceramic-matrix composites.
Hennessey installed cheap spacers on my 2018 on front tires only due to the large Brembo brakes they added... i think they do this so they can use the same method wheels on all trucks no matter if brembo is added or not.