How would they enforce this on open source projects without companies behind them?

This doesn’t require the user to be able to block, it’s required that there is the ability to block a user from the system in general.

I’m using fedora as my work system, because I have a relatively new laptop that needs the new kernels. Haven’t experienced anything you’re describing. Are you on fedora regular or on sliverblue (the immutable version)? If you’re having issues running the newest kernel, follow the fedora documented way to build and run your own. I did just that when needed a prerelease kernel and it worked out fine. I usually upgrade to a new release by the end of the cycle, so that the new version had 6 months to mature. I never immediately upgrade.