This is big news.
This letter indicates that the county insurance pool will no longer cover Public Records Act claims by counties when they get sued.
This is probably because some counties, like Jefferson County, made some questionable decisions and got sued, like by claiming the "pizza privacy exemption."
So if you're suing a county for a Public Records Act violation, the county might be on the hook itself for the money (fees and penalties awarded to you and the county's own defense costs).
This might actually encourage sensible settlements by counties. Funny how making people pay the costs of their own actions makes them a little more careful. (Of course, when counties pay for their actions, it's with your tax money. But even this seems more like "their" money than insurance money.)