This already exists in rugby. It's called the Television Match Official, and provided the NFL doesn't screw it up (that's a big ask, I know), it would really help with pace of play and making correct calls.
Its my understanding that NY is only involved with booth reviews and challenges. With a sky judge aiding in ball placement, turnovers, receptions, etc, it shouldnt get to the point of involving NY imo. For instance, just in the postseason the Chiefs got away with hitting Baker Mayfield in the head, hitting Josh Allen in the head and a helmet to helmet hit on Rashad Higgins that caused a fumble out of the endzone resulting in the Browns losing possession.