Well if the fuel figures from myradios are true 2.9T in a 320 is significantly more than the Qatar final reserve +5mins.
1.2T ish = 30 min final reserve leaving 1.7T holding and alternate fuel.
I wonder if the Juneyao crew knew the Qatar had declared an emergency and that was why they had been asked to break off their approach? Its easy to judge without all the facts...
Sure if they were in the loop about that its unforgivable with that much left i the tanks.