The JSF is no option for Pakistan. However, as the Pakistani economy grows and in the next 3-5 years after, the US gets interested in massive investments in Pakistan (means profit for the US businesses), that's when the JSF becomes a reality.
Do note, that LM had Pakistan on its marketing list of potential calendars till 2014 listed as a potential customer by 2025 (I assume that's because they had calculated some growth in Pakistan's economy). But they removed Pakistan from the list.
But the J-31 here, takes the PAF into the 5th gen world of a few air-forces and that by itself means a lot. Plus, it introduced Stealth related industry in Pakistan as Pakistan will produce some maintenance material to control the costs as with everything they get from China. Trained labor on stealthy platform, its maintenance, avionics, advanced radars, EOS, etc,etc. So acquiring this platform, creates trained people, advanced processes and technologies inside Pakistan as an industry, that only less than 4-5 top end countries have today. Pakistan can apply stealthy principles, technologies and materials produced internally to its own Cruise missiles, the JFT program, internally produced Drones, etc, etc. Imagine the possibilities and the capability this would provide to Pakistan.