Which CPUs accept microcode updates
AMD has closed its Operating System Research Center since November 2012: See this Phoronix article
The link to AMD's Operating System Research Center doesn't work any longer.
Maybe the section should be updated by removing the information for AMD users and keep only the information for Intel users ?
Grub config file instructs the user not to manually edit it.
It might be worth making some kind of note that grub does not expect users to be editing the config file since the wiki presents manually editing this file as an option.