perhaps due to tankering fuel into KTM (which is a regular practice by most airlines)
indiGo doesn't tanker fuel to KTM and has brake fans equipped in their 320s... most of the time you're taking off with brakes usually being less than 100 degrees C
The eagle-eyed might also notice that the flaps are not set (down), i.e. for the passengers to slide down, if they're evacuating via the over-wing exits. That would most certainly be due to a lack of hydraulic power
that is not a part of the evacuation procedure... the overwing exits have slides as well