Amazon currently has a new Amazon Health Rating (AHR) that is in beta test. You can find it in the Account Health Dashboard. The idea is for this to be an early warning system for sellers. Many sellers have complained about the capricious nature of account suspensions. It usually comes out of nowhere.
The AHR is designed to measure the quantity and severity of your account violations. If your AHR is “At Risk” or “Critical” your account is at grave risk of suspension.
Policy warnings will be removed after 180 days. Thus, it is important to be proactive and avoid policy violations before they sprout.