I'm honestly not even sure a competent administration could win this lawsuit (it's not as cut and dry legally as we all might prefer), but I'm pretty sure the Desantis Admin will NOT win.
Thus, in my CT theory here, once it's decided against the plaintiffs (as is the point), people will assume moving forward that AI companies can't be held responsible for how people use their product, what advice they act upon, etc. Not even when it's kids who committed suicide using methods described to them by AI. Do you know how much a court decision like that will be WORTH to these AI companies?
When Democrats take back the House, the existence of this "ongoing civil case" from Florida will be a cudgel with which the minority can leverage if Democrats start talking about passing legislation requiring safety regulations for AI. "We MUST SEE how the Florida case against OpenAI comes out before making new laws!", the GQP trained flying monkeys will screech. Even though it's outcome shouldn't matter one whit either way in terms of what regulations are made in response to the scourge of "AI for Everyone". And the lawsuit conveniently will probably drag all the way until the 2028 election.
Legislators already know deaths are happening and probably should take a number of well-considered steps to help stop it, regardless of whether OpenAI is found financially liable in this one case.