Excerpt from a Reddit reply by a System76 employee about age verification laws at the OS level.
"We at System76 are talking internally about what this bill, and the similar Colorado bill, would mean for our business. Any provider of an operating system that may be used in these states would have to do the same - this includes Canonical, elementary OS, Purism, Red Hat, SUSE, and many more. Community developed operating systems offered for free may even be required to comply or face fines, likely directed at whomever provides the OS in these states. If the operating system is developed internationally, but there is any business relationship with anyone in these states including support, pre-installed hardware, or otherwise - it is likely to make someone liable. The fines for non-compliance are plainly stated in the bill and are extreme. "