It's definitely one big reason other than payment required for equipments needed to be bought. As per reports, India managed to damage two of their Airborne Early Warning and Control (AEW&C) systems which they urgently need to establish back. And they have made many new deals for fighter jets and other equipments from China. 

Does that factor into this increase in military spending?

Undisciplined

econ

Pakistan boosts defence budget by 20% but slashes overall spending in 2025-26

Coinsreporter

They have claimed freedom before sometime. But maybe Pakistan had again taken control of some of the important areas. Although a big part of it is still under BLA's control. I think all the Baloch territories need to be united , which they aren't, before asking for sovereignty from the world. 
In short the fight for freedom by Balochistan continues. 