Agreed in principle, but given the simply fact that there are even older types still operational, the PLAAF even introduced several JJ-7A just last years I cannot think that they will be replaces earlier than say the final J-7E/Ls or J-8DHs.
Again, I fully agree with you and also think that - as already done - older A-models are transferred to second-grade units but retiring before the last J-7/-8 si gone, I don't think so.
Not retire them early but not upgrading them as much.
When the J10As were introduced, the number of training hours per pilot was basically doubled. Also, several pilots shared a plane due to slow ramp up in manufacturing. They still wanted as many pilots trained as possible when new J10s arrived. Compare that to older J7s where it was mostly one pilot per plane.
I would think the original J10As still got a few good years in them, but it doesn't make economic sense to upgrade avionics for a 2nd line unit that won't have too many years left.
I was told before that the air frame life increased by 40% or more between the years 2005 and 2010 solely due to improved manufacturing techniques and better material. Probably improved even more now. My uncle's specialty is in the structural/air frame and aerodynamic design. Basically when they first designed J10 the limitations were always what van be manufactured and not what's the engineering limit. When J20 started it was what is the engineering limit, there are no manufacturing limit.