Its interesting that most of the August 1st J10s seem to be twin seaters, which would suggest that these are new, and possibly custom, built airframes. When I first heard reports that the Aug 1st were getting J10s, I assumed they would be getting some early production birds, possibly the CFTE birds, with all new buids going to front line units.
It would suggest that the PLAAF has decided to slow the pace of J10 induction if they managed to squeeze capacity for their display team to get new build J10s instead of focusing on building up new regiments as fast as possible.
I wonder if this is because of the advanced stage the J10B has reached and the PLAAF is just waiting for testing to be completed to go with that over getting more J10As.