I have seen nothing indicating Iowa is subject to this. CUNA (CU trade association) published a list not long ago of states it applies to, found
here indicates that states that require both disclosures are:
Requires both, placard and electronic display:
Illinois
Nebraska
Nevada
New York
Vermont
Wyoming
That being said, you may want to try to verify it with the IBA. We are leaving ours on, since we have plaques that are screwed into the machines and just figure we may as well leave it and just stop verifying that it's still there on a regular basis like we had been.