Keeping all the rhetoric aside, as a man of science, I must congratulate Pakistan for having accomplished this feat if they really did it on their own. These are some of the instances Where I feel they should be a little bit more transparent. Anyways this particular launch does seem legit and also if one observes carefully, this one is "different" from the previous launch. Which also proves that previous launch wasn't actually a Pakistani launch.
I'd like to highlight that capability to achieve a controlled underwater ignition and clearing it off water is nothing short of really good achievement for Pakistan. What is also commendable is the fact that Pakistan somehow is able to produce the system in house without actually having serious R&D in any of the specific areas of aerospace or sub systems. For instance Pakistan does not have any R&D in micro turbofans/jets, aerospace grade actuators or navigation boards(military grade), yet they've a working system at their disposal.
For India it would indeed complicate the nuclear equation when Chinese submarine first start arriving in Pakistan. That's the time when these nuclear armed baburs would be integrated onto a real naval platform. All the gossip of changing the combat management system of Agosta to accommodate Baburs is way off the mark for the simple reason that combat management systems are highly proprietary and one doesn't have authorization to tweak the code to incorporate let's say a mission planner for the cruise missile. Mission planner is a software that is embedded into the launch platform that provides a way of navigation way points to the missile. These navigation way points form the outer loop that the control system is required to track. I've published one such paper at AIAA(American Institute of aeronautics and astronautics) and another one using advanced neural networks based controller is on the way.