Hi CottageLV,
For the size of the next generation of PLAN surface combatants:
Propulsion ultimately determines the size of the vessel. From a few interviews of retired PLAN officers and ship building experts in China, I speculate that the next generation fleet will be consist of destroyers with 4 gas turbines, with frigates with 2 gas turbines. In this case, it's very likely that the next generation destroyers are ~9000 ton, while the frigates are ~5000 ton.
For the Ukranian engines problem: Yes, it has been solved