If anything, the POSIX passwd specification should be updated to include age instead of introducing yet another dependency on systemd for something that affects the entire ecosystem.
But that means a user's birth date will be public viewable, for some people that would be an issue. In my opinion. bdate should not be stored anywhere in Linux or any UNIX type system. Linux and the BSD should ignore these laws completely and we move on from this.
I still do no understand why the Linux Foundation is not chiming in. By keeping quiet all the LF is doing is reinforcing the perception that LF is fully owned by "Big Tech".
Go try implementing accounts under FreeDOS or CP/M.
Now potentially a 18+ game can be showed to billions of native (and non-native) English speakers from nearly any OS sice 1979, even under a PostScript file (zmachine.ps), albeit it needs to be extended.
This law it's idiotic and it shows. Will they ban retrocomputing with Amiga OS 3.1 running on FPGA's or what? They can run the modern web with TLS 1.2/3 with AmiSSL. They can run IRC against Bitlbee and login into Steam, Jabber, Discord and Mastodon with relative ease. Gemini can access most JS-less webs at gemini://gemi.dev and Gopher clients for sure it might be some adult content referenced at gopher://magical.fish and gopher://sdf.org, even if it's just mildly NSFW, such as harsh language and sex references. The Javascript-less web, too. Usenet, more adult discussions and content, maybe with heated flame wars. And for sure they can run Frotz with that mentioned game game, at full speeds.
You're free to ignore them/leave empty unless your server's policies say otherwise.