You're not thinking creatively enough. The way things are going, the argument will be that uncontrolled installation of unregulated Linux distributions empowers pedophiles to distribute CSAM, so government will start demanding new motherboards to only allow the installation of properly vetted operating systems that implement extensive, impossible to disable, system monitoring to make sure no CSAM can be distributed with it.
Only big corporations with a proven need for maximum performance (and governments, evidently) will be able to buy special, unrestricted motherboards, and they'll need special authorization and a proven internal governance system, subject to periodic government audits, to show they aren't allowing CSAM on their systems.
Evidently, politicians and CEOs will be free from such obligations, because they're Very Important People acting in the National Interest.
And once this is in place, the tightening will continue at a slow but steady pace.