This is what people are speculating just because 17 is inevitably going to be a more optimized design than the 16, but there is no actual evidence that the 17's hangar is larger than the 16 enough for TWELVE more J-15 sized fighters. IMO far more likely is that the hangar is just a little bigger, enough for a few more helos. I think it is also possible the hangar size did not even change at all from 16 to 17.

Those photos at the top of this thread are just a photo op. It has nothing to do with actual flight deck ops in real life because at the end of the day you would need to find a place for all fighters on the flight deck (-1 landing fighter) but outside of the landing strip area, which is bound by the dotted white and red line.

My rough eyeballing of the 16's flight deck minus the landing strip suggests 17-18 J-15s could be stowed out of the way and still allow a final fighter to land safely. This stowage would of course preclude any launches as it would involve putting multiple J-15s on the launch ramp itself. You would need ~18 more spots in the hangar itself to get to 36 fighters. I think this is theoretically possible based on drawings that various fans have done on the Kuznetsov hangar over the years. These drawings OTOH need to be taken with a healthy dose of skepticism as they invariably involve Su-33s being packed into the hangars like sardines in a can, which if you look at actual Kuznetsov hangar photos (or even Nimitz hangar photos), this never actually happens.