The point is that you won't be able to just install a Linux distro of your choice in this world - your computer will only run approved OSs that have gone through some kind of certification process to make sure they enforce age-verification content. If, say, the Debian foundation doesn't want to add these mandatory controls because they feel it goes against the spirit of Debian (not to mention the huge issues with the GPL), then your new computer just won't be able to run Debian anymore. And something like Kali would be right out, of course, since anonymity is not compatible with age verification.