Routers are just computers with radio peripherals. You cannot lock them all down, the problem is that overnight all consume router hardware will be stuck on broken insecure defective proprietary firmware that never gets updated.
You can always build your own router, though.
But the FCC rulings might also apply to drivers for radios. Right now you can get any ath-9k hardware and do almost anything you want to it with a Linux kernel since all the driver infrastructure is open. With ath-10k, newer Broadcom parts, and all Intel parts they include proprietary firmware blobs to restrict what you can do now, though.
It is likely these rulings will push the OEMs of radios to start moving more functionality into blob payloads, which will include future iterations of the raspi.
This is why these kinds of decisions are incredibly ignorant and stupid on the part of the FCC. They cannot retroactively lock down all existing radio technology. Hell, they cannot reasonably expect to ever stop someone who wants to use a radio to congest the RF bands of someone else from doing so - it is trivial to assemble your own scrambler. This is simply an emotional response to criticisms about the relatively open state of routers and radios in recent years and how some bad actors have been taking advantage of that open access to more easily harm networks.
I don't understand this, does this really mean I can't even buy an open Chinese router for example, run my own/open firmware, comply and with all regulations regarding power and frequencies, but it is still illegal?
So because I can theoretically break the law if I intentionally alter the firmware to broadcast on a forbidden frequency I am already punishable by law?
So.. what about knives and stabbing and all those types of arguments? I can almost not believe this!
Under these new FCC terms the violation is giving you the ability to change your radios power. That would apply to imported hardware from China - notice how all that stuff has FCC approved labeling on it.