Armenia regaining those lands would be like Germany regaining Kaliningrad.
Bad comparison. Turkey was an aggressor, which got rewarded for its agression and genocide. Germany was an aggressor, which got punished for its aggression (and indirectly its genocide).
Anyway, the point is that it would basically entail massive ethnic cleansing for Armenia to regain those territories.
It's almost impossible not to make an Israel comparison here...
You needed to ethnic cleanse a few hundred thousand to create Israel, and it was in the middle of a war and it already were 50% Jewish. Here you need to ethnic cleanse 5-10 million to create Wilsonian Armenia, and while a small Armenian population may hide in the region (as Muslims), they at best make up a 100-200 000 people. Also I don't see the Armenian diaspora return to this area, so you simply give a large empty area to a small state with 3 million people and a low birth rate.