I wouldn't call the status on the EO PDS (or as some call it, the EO DAS) on J-20B that quickly.
On J-20AS (twin seater), on the first prototype 2031, they seemed to have an aperture on the dorsal nose in front of the canopy, but none on the sides:
On the second prototype 2032, they seemed to have apertures on the sides of the nose (behind the radome), but didn't seem to have it in front of the canopy.
I'm not sure why they would differ between having apertures on some prototypes and not others, but clearly it goes to show that we cannot yet say what the final state of the apertures will be on the final production J-20AS.
And I would say the same principle should apply to J-20B.
Personally, I do not see a reason why they would remove the apertures on the production J-20AS and J-20B.
I do not have a definitive hypothesis for why they would alternate between removing some and having some apertures between different prototypes, but I wonder if it is just because the EO PDS subsystem is sufficiently mature such that installing all of the apertures on each prototype is not worth it.
Time will tell -- but IMO our operating hypothesis should be to wait for what the final production representative fitout for J-20AS and J-20B should be first, given we have evidence that aperture presence has differed between successive prototypes.
