At the very least air frame number #31 is also included. But as usual this is a hodge podge of footage taken anytime from J-15 induction in service to this year.
Also I got J-15 #64 on my hard drive from the 20.02.2021 on land and #67 from 22.04.2021 so we definitely new before about 6X. And
was spotted as early as 17.12.2020 during carrier operations according to the file date on my hard drive.
But I don't quite get the point. There is a good chance they had quite a few J-15 for a while and only show them to us now since they have at least for J-15 nigh perfect control about which serial numbers they want to show us so we have to assume our spotting is delayed by an arbitrarily large timespan.
I personally can't say with certainty that the aircraft are numbered chronologically (later serial <--> later arrival date) or if they break the order in which they get inducted at times which is why I don't exlude an alleged #57 joining the fleet after #6X but vice versa I don't see a reason to believe so either. They could easily have footage of it by now even if they have inducted it after the later serials.
The 0 digit for the tail number for J-15s has no line in the middle going by previous serials. But the speed of the aircraft combined with the lack of a bright illumination source means it is somewhat blurry. If it were a 0 however I'd expect the large shape to stand out more than that and from further apart from my screen the contrast does look very closely to a 5 especially over the whole sequence.