Using the FC-31 as a basis for a next-generation naval fighter is different from directly injecting cash into the FC-31 program. So unless the PLAAF goes for the FC-31 the development of the J-35 won't have too much of an impact on its appeal to the PAF.
The closest Chinese combat aircraft to the Rafale is still the J-10C, and it also happens to be the only newer-generation platform available for export other than the FC-31.
Yeah, if I were the PAF and I was thinking about buying J-10Cs, I'd probably rather spend that money on buying more Block III JF-17s instead. Adding on a separate logistics chain for what would likely be a relatively small number of J-10Cs for the capability it provides vis a vis JF-17 probably isn't worth it.
In the longer term, PAF will obviously need a 5th generation fighter, and I think FC-31 has a good chance of being a basis for that.
But let's not get too hung up over what exact path it could take.
Yes, obviously the chances of PAF directly adopting the FC-31 we've seen SAC testing over the last few years isn't going to happen.
If any nation adopts the FC-31 outside of China, it will be a variant derived from an in-service variant that the PLA itself has adopted.
.... that is to say, I can see the PAF adopting a variant of the J-XY (which the PLA will be fully funding development and procurement of) perhaps with some changes like removing the foldable wings and reinforced landing gear (e.g.: an "F/A-18L" to the J-XY's "F/A-18". Or perhaps PAF might even just adopt the J-XY wholesale with minimal changes in avionics -- there's a precedent for that after all, with carrier based fighters being sold to customers for exclusive land based use.