Personally, I think there is zero point in skipping microcode updates when you are already executing non-free microcode when the CPU comes out of reset.
Yeah, this just seems like burying one's face in the sand to me. Every Intel CPU runs non-free software. It's nice that there are attempts to remove and/or replace Intel ME, but that's just step 1; Intel's microcode, which has never been decrypted or reverse engineered, undoubtedly contains a lot of very software-like bits, and with the upcoming SGX, those bits are suddenly going to get quite hostile to the owner of the device, by locking the OS out from inspecting running programs. Running from ROM or from a blob provided by firmware ought to be considered immaterial; it's not like Stallman would be okay with running Windows as long as he stuck to version preinstalled on his device and never installed any updates.
I believe AMD is no better. But ARM CPUs are getting faster and faster, and most of them have no upgradable microcode, which probably means little or no microcode at all; if you truly believe in free software, get something with one of those (and hope you can avoid the nightmare of ARM SoCs' GPUs). Having the HDL source to the CPU would be even better (see lowRISC), but one step at a time...
