This page is a running list of Open Source Operating Systems (Linux & *BSD distributions, etc.) and what their current status is regarding age verification.
There are several locales which have laws (in various stages) which require Operating Systems themselves to perform some level of age verification and reporting.
Passed OS-Level Age Verification Laws: Brazil, & California.
Proposed OS-Level Age Verification Laws: Colorado, Illinois, New York, & Michigan
So MidnightBSD is caving to this after that noise they made. ("temporarily" forbidding use, until they can implement it).
You can bet that Arch will upgrade to every version of systemd, as soon as it comes out. So I better get working on something else, because FUCK anyone that implements this. Not that I couldn't remove it from systemd, it's a matter of principle.