Systems and methods directed to evaluating potential loss of separation are provided. The method continuously receives a host status data, as well as traffic flight information for neighbor traffic. Responsive to a controller pilot data link communication (CPDLC) message with a flight profile change, the method continues by processing the host aircraft status data and the traffic flight information, to (i) construct a modified host flight path based on incorporating the host profile change without delay, and (ii) construct a neighbor aircraft trajectory for a neighbor aircraft. The method processes the modified host flight path and the neighbor aircraft trajectory with loss of separation (LOS) rules, to identify a potential loss of separation (LOS) event. Responsive to identifying the potential LOS event, the method continues by annunciating information describing the potential LOS and its location.