Think "processor" in the sense of "coprocessor", not in the sense of "CPU". There are enormous numbers of chips which embed multiple processor cores, often with heterogeneous architectures. Consider Intel's own Movidius VPU, which includes two different LEON cores (SPARC) and 16 SHAVE cores (VLIW vector processors) all on the same die. There are many options for the cores used in such a device - ARM, RISC-V, MIPS are common - and now Intel wants Xeon cores to be an option too.