There wasn't any genocide in Ionia carried by Greeks in 1919-22. The actions the Europeans contemned were incidents of slain of Turks by greek troops provoced by prior slains of Greek civilians and soldiers by Turk irregulars. These actions are not justified, but they couldn't have been prevented, especially after the pogroms against the local Greeks during the Balkan Wars and WW I.
Venizelos had asigned Fotiades as High Commitioner in Smyrna and this man was very careful about the behaviour of Greece towards the local Turks. He was even accused of beeing pro-Turkish!
In any case the Greeks would form an overwhelming majority in the region, since all Greek of Anatolia (i.e. form the region of Antalya, Cilicia, Cappadocia, Pontus etc) would flow into the Greek-dominated areas. Note that in 1922-3, during the exchange of populations, even after many died during the war and the procedure of the exchange, 1,500,000 ethnic Greeks flew to Greece.
If Greece were able to maintain the yellow areas after the Graeco-Turkish war, it is almost sure that there would be another Graeco-Turkish war, probably in the mid-1930's. I can't see Greece loosing this war either, except if Italy joined Turkey. In that case the result is under question.