If you read what I wrote, I don't think the guns are the main reason for the delay in the Type-54 either.
Yes, the Chinese Navy is busy with AEGIS Destroyer production and commissioning.
For long range air defence, large missiles are always going to be needed.
And for long range land attack or anti-ship, they still need large missiles.
So the AEGIS destroyer main armament of VLS cells won't become obsolete for its entire service life.
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But for a Frigate, whose main missions are ASW and medium-range air defence for a convoy?
ASW warfare is definitely changing with the advent of drones (Airborne/Underwater/Surface) and new detection technologies (LIDAR/SQUID/etc)
How well is each system going to work? We don't know yet because it is all so new.
Then we have potential HVP/Railguns, both of which could change the medium-range air defence calculation.
This takes time to work out, because they need get the experimental data to figure out what works, how much it costs, and then what is the optimal combination of systems and hull.
And in the meantime, they're just proceeding with the Type-56 light frigate.
The production of 054A has not been completed yet. That is most of the story.