Sure they did. They invaded the part of Aremina that was literally inside Azerbaijan's borders, because Armenia seized it through conquest a few decades back after the USSR's collapse, and proceeded with a "population exchange".

Btw how did "population exchange" become popularized to use instead of ethnic cleansing? I genuinely don't know, but I've seen it alot lately.

I mean Azerbaijan have invaded Armenia proper in the past in skirmishes, but Armenia also invaded Azerbaijan and gained territory from it... They've also both committed genocide against each other, with the region in the news recently for Armenians being expelled/killed/leaving following Azerbaijan recapturing it only being majority Armenian due to the Azeris being expelled/killed/leaving in the 90s...

In reality it's a situation very similar to Israel/Palestine where regardless of how it started/what the "original" status of the land was, both sides are so overwhelmingly awful in their actions that there's no good guy, but of the four places mentioned only Palestine (Hamas really) has such a disdain for all people, even their own, that they stand out as worse than the others to me