Colorado and California age verification bills exempt open source operating systems
(www.gamingonlinux.com)
Saw a comment on an article about this specifically.
"All the "age verification" bill are unconstitutional 1st Amendment violations and can be struck down in court.
Code is expressive conduct under Bernstein v. DOJ and Junger v. Daley.
Compelled creation of expressive content is still compelled speech (Wooley, Hurley, Janus).
Age verification mandates require developers to author, maintain, and deploy expressive logic they would not otherwise create.
The state cannot force a private actor to speak, design, or encode a message or system that expresses the state’s preferred policy. "
So it seems, if this is sound, that an open-sourced software, being from a private entity, cannot be compelled to implement something like this without infringing on free speech. Maybe they go after the first amendment, but that's an entirely other legal struggle than this looked initially and would be significantly harder to do.