Demetrias in Thessalia is named after, and founded by, Demetrios Poliorketes, son of Antigonos Monophthalmos, and father of Antigonos Gonatas, the king of makedonia when EBII begins. For Antigonids it is natural to honor a member of their dynasty, but not so much for other greeks, especially Epirotes and Chremonidean league. The situation is similar to how seleukids dont keep the name Ptolemais-Akko. Since both epirus and KH often take Demetrias, it would be a nice flavor if it was then renamed. unlike akko, demetrias was afaik founded as a wholly new city so there is no previous name to revert to. Unless it can just be called Larissa instead, but those are of course different cities, and i dont know if EB in any other case ever "rename" a city to a different city.