1. Whatever final outcome of war, lessons need to be inferred&learned, so independent commission? No single cause behind the loss, and one needs to look at both structural factors and agency. Looking at the latter means looking at conduct of both previous and current leadership.
2. I am not privy to Armenia's domestic politics, but even a superfluous observer would wonder whether Pashinyan's relentless focus on prosecuting predecessors prevented him from spending more time on national priorities, e.g. hardening defenses.
3. I think, given Turkey's military involvement Putin should have intervened early on regardless of personal relationships, but looking back - was really worth it to pursue prosecution of Kocharyan and CSTO's secretary Khachaturov, knowing it'd alienate Putin?
4. More important, why toughen the negotiating position unless you have expanded your BATNA by, say, qualitative improvement of armed forces?
5. Also why procure heavy multi-role fighters worth millions of dollars/capable of reaching Ankara, if the April 2016 war demonstrated the effectiveness of attack drones?
6. That said, as I said above, both predecessors' conduct and structural factors would have to be examined thoroughly if the goal is to discern confluence of what factors led to this loss and what lessons need to be learned from it.