The problem that lead to the Linux 5.3 changes was early boot. Even if your system has a camera early in boot it is not likely to be initialized. I fear it might be difficult if not impossible to have a generic kernel that gets entropy from an unknown model of camera early in boot.
Good point. Where to get randomness when nothing is initialized yet is a tricky matter. I wonder if RAM could be mistuned to generate enough randomness. Certainly not always and everywhere, but probably usually, if you are running on bare metal.
If not, whoever is has plenty of randomness to hand over.
