

Your example relies on some assumptions:
- User has chosen to opt into filling in their actual DOB (not some nonsense date)
- User has app installed that fetches the DOB from userdb
None of these assumptions are garunteed by the merged code into systemd. The following are optional, and not required as a result of the code merged into systemd:
- Merely setting data into the DOB field
- Attesting DOB honestly
- installing some prying application that queries
It’s possible to put your full first and last name into your user, so by your logic the first and last name fields of the user profile should not exist.
Did that help identify the absurdity of your argument?

Despite all of us collectively agreeing that the law is dumb/flawed, the 40 M residents of Cali should have the liberty to be able to use distros that depend on systemd, legally. And, the developers of these distros using systmed (whether you interpret the law to see them as OS providers or not) want to be able to provide these distros legally.
Yes, but not all apps. While the CA law mandates that app developers must use some API to get the age bracket, the merged code into systemd is not causually related to all apps actually implementing and using the API. Just because systemd merged this code does not inherently result in every single user application querying this, nor does it force you to install apps that do query the API. One may freely choose to not use apps that require it. If one needs an app that requires it, one may set a garbage DOB to their user. I don’t see this as an issue. Do you?
It seems you disagree with the law (so do I) but are blaming the wrong person here (author of merged systemd code). I maintain that complying with the law is harmless, and thus it is beneficial to add this DOB field to the userdb json, because in all cases of some distro user using their computer, they are not compelled to compromise their personal privacy.