I note that the constitutional white paper which preceded this law does not really address the preemption or dormant commerce clause concerns I raised above, but mostly limits itself to the First Amendment:
I agree that the First Amendment (as incorporated by the Fourteenth) is not implicated by this law.
ETA:
Requiring an operating system sold or used in a state to transmit the owner’s age-range based upon the device’s registration data is a minimal burden that neither interferes with interstate commerce (i.e., it does not violate the dormant commerce clause despite potentially broad extraterritorial effect outside of the enacting state), (see Nat’l Pork Producers Council v. Ross, 598 U.S. 356 (2023) (upholding California statute requiring all pork sold in state to meet animal-welfare requirements)) …
The statute as ultimately passed by California is not limited in application to operating systems sold or used in-state. If it were, I would concede the dormant commerce clause issue.
~Max