> limitation on the First Amendment
This suit has nothing to do with free speech and the F1A provides no relevant protection here. This prosecution is under consumer protection law. Broadly, the cause of action is "you negligently sold a defective product which you knew (or should have known) actually causes harm or is likely to cause harm." Proving negligence (willful or otherwise) depends significantly on things like the sales and usage context as well as claimed features of the product along with disclaimers, disclosures, existing practice, prior knowledge of actual harm, etc.
That the product or service in question included supplying information that was publicly available elsewhere wouldn't be an effective defense against claims of willful negligence or reckless endangerment. For example, rat poison is sold in in certain retailers in packaging with copious warnings and successful prosecutions under product liability or consumer protection law are rare. But if another company sold rat poison in bright pink boxes with a cute cartoon mascot and no warnings in toy stores - and then kept selling it after they knew three children had bought it and died - the fact the same chemical compound is also commonly sold in hardware stores wouldn't be relevant.
To win a judgement, the AG will need to prove that ChatGPT was clearly a dangerous product and OAI acted negligently in supplying it to customers it knew (or should have known) were vulnerable. This will be quite a stretch under existing law. I suspect the AG has no intention of taking this case to trial and, shortly after the November elections, will settle for a lump sum fine paid to the state treasury and a vaguely worded consent decree which mirrors internal policies and product changes OAI has already adopted to minimize liability.