[caspianm]

Doesn't this law just let parents set up age-labelled accounts for their children with the idea that apps not suitable for children won't be allowed under those accounts?

Seems no worse than what mobile OSes already do and not that bad a feature for a modern general use OS (except if you monitor someone's age bracket and noticed the exact day they change, you can work out their precise date of birth.) It does seem unsuitable to force it to be added to embedded OSes, freedos, CP/M and historical/retro OSes in general.