a KJ-500H with only 2-digit serials ... so again something new; no longer the 5-digit Naval Division numbers and also not the older 4-digit numbers....
We've been pretty lucky for all these years to even get the full serials clearly presented in large size. That may have come to an end.
Similarly to how carrier borne j15s only have two digit serials, probably only referring to intra unit airframes. Russian air force has a similar system with just two digits being clearly visible. (And the full serial being placed elsewhere in smaller size)
So the full serial may be much smaller and placed somewhere where it is less likely to be picked up by a telephoto lens from the ground.
Yes, it may make tracking planes in different units much harder.