It isn't just Citizens. Allstate (aka Castle Key) issued notices of non-renewal a few months ago. Our agent did help us find another company, but we will pay more for less coverage. We've had 2 claims in 20 years, one from Ivan and one from water damage when our PBU plumbing in the attic (dreadful combination!) was punctured by a roofing nail.
The agent who worked with us to find our new coverage said that all insurance companies in FL are looking for ways to offload policies. They plan to go after homes with aluminum wiring next, including those that have Alumiconn.