This exploit isn't at all related to the Intel CVE, just a coincidence they came out around the same time. And an instruction set that strips everything but the necessary instructions sounds a lot like ARM or RISC-V. No need to re-invent the wheel.
Have you, by any chance, looked into the contemporary ARM instruction set? Just the list of base instructions for A-profile with 1-2 instructions per line takes 14 pages. And then there are SIMD&FP Instructions, SVE Instructions, SME Instructions. Oh, and also M-profile, and Thumb / Thumb-2 instructions encodings, and more.
A small glimpse could be made here: https://developer.arm.com/documentation/ddi0602/2023-09/?lan...
Eventually something will have to change, and is it less work for Intel to shift to ARM than to strip x86?