I remember after last campaign campaign i worked to earn my medal of altana to be ready to partake those fights... But that campaign campaign never happened again!
I wonder if there is some other reward for medal of altana aside access to those battlefield. The medal is something similar to others expansions ranking, and all of them was related to the highest value item in game (nation ranks to have access to relic weapons, mercenary ranks to have access to mythics, coalition ranks to have access to ergons), so kinda disapointing the reward for medal of altana, considering that medal takes as long much longer than mercenary rank to cap, just behind coalition ranks. The correct order would be to make empy weapons just available with medal of altana, but no.