According to der8auer, Threadripper is an Epyc CPU configuration with four dies, each packing eight cores. Threadripper only uses two of the four Ryzen dies mounted on the PCB. The other two aren’t functional. Some have speculated whether or not they are "dummy dies" but Der8auer sticks to the claim thay are Ryzen dies.
Still I wonder if 24 and 32 core Threadripper CPUs would be manufactured in the future?