Does Emperor's Divide move units to base and they are still ready if they were previously ready at battlefield?

Yes, when you use Emperor's Divide to move units from a battlefield to your base, they remain in their current state. If they were ready at the battlefield, they will be ready at your base.

According to the general mechanics of moving units (as supported by the FAQ regarding Ride the Wind), units are recalled or moved in their current state. Since Emperor's Divide does not contain any text instructing you to exhaust the units being moved, they retain their "Ready" status upon arriving at your base.