None of that is a good rationale for patching the firmware to retroactively remove things from devices that were sold years ago. It's an abuse of a mechanism that's ostensibly meant for security fixes and maybe perf improvements, which is a dangerous game because it incentivizes people to just not update the firmware at all, which is a worse scenario for both parties than just resolving to not include the feature in CPUs going forward if it's such a huge loss to include it.