Well one has to admit, the PAF's been particularly quiet about the HMD/S and HOBS work regarding JF-17 (besides stating that the JF-17 will have the capability). This is in contrast to the wealth of information we got about JF-17 using SD-10, LS-6, C-802 or even Ra'ad and CM-400AKG.
If the HOBS solution was simply the PL-10, then we would have heard something, we haven't. Of course, systems such as MAA-1B or A-Darter would likely kept under-wraps, so as to prevent international (read: Indo-US) scrutiny and pressure. The lack of information thus far could easily point towards the South African-Brazilian solution.
On the other hand, we do know that the potential for Pakistan to acquire and/or develop the requisite technology is already there, e.g. Pakistan's various MoUs with Turkey, Pakistan's ties with China, Pakistan's approach to Brazil, residual links with Denel, Selex-Galileo, Saab, etc.
An indigenous 4th or 5th generation HOBS WVRAAM is a possibility, this is the country that came up with Ra'ad and Babur after all (in addition to parallel nuclear weapons programs). In fact, an indigenous solution may be the easiest (short of China) in the sense that it'd be the only program has no chance of being interrupted by foreign pressure.