No. Malpractice insurance would be at the professional level. There could be lawyers using a legal chatGTP, but the professional liabilities would still be with the licensed professional.
More legal malpractice? No, because they aren't attorneys and you cannot rely upon them for legal advice such that they'd be liable to you for providing subpar legal advice.
Why? Because there's no word for "insurance of AI advise accuracy"? The whole point of progress is that we create something that is not a thing at the moment.