Totally agree with your post, except for the above part.IMO it would be something akin to the JF17 program
In my humble opinion AZM-NGF will be a new true blue low observable stealth design which may borrow some things from the J-31 & TFX.
It will become reality with Chinese help.
Things learned from the Thunder program will help develop the the next level systems required. The design (itself) does not need to retain any familiarity with the Thunder.