Its about time. Building just 3 of a class (or 3 + 3 in A, B-upg format) is not sufficient given lack of true economy of scale and the force levels PLAN has achieved already. 8 ship builds is minimum going forward.
BTW, INS Imphal did a test:
Not so open-and-shut, champ.
The PLAN has been feeling its way cautiously forward from its laser-focus on coastal defence to (first) a near shore navy, focussed on anti-submarine warfare, replete with weird schemes for underwater traps and obstacles to get hostile submarines lurking too close to Chinese shores (too close = 1,000 kms, give or take half an ocean), and then (second) a proper blue water navy, capable of operating at distances from Chinese shores. In parallel, they were jamming these vessels with technology - on better, more powerful radar and sonar in the matter of sensors, and vertical launch systems with more and more capacity (currently 3 or 4 missiles can be sandwiched into the same VLS tube), and CIWS and ASW armament outside missiles, and, to fit in all these, different combinations of hull size (beam and length, and displacement) and propulsion and transmission systems.
The situation about their destroyers will help to understand what they faced and addressed.
They began by 'reverse-engineering' Soviet naval craft. Still in inventory is the Sovremenniy class destroyer. They shifted as soon as money started pouring in to, first, the Type 051, of which only one or two sub-types remain (Type 051B, and Type 051C), then the Type 052, that is now present in all its variants, Type 052, Type 052B, Type 052C and Type 052D. Finally, they built the big ones - for want of a better description than destroyer, we can them 'super-destroyers', or, in the interests of orthographic and nominal parsimony, 'light cruisers' (WWII Royal Navy light cruisers were around 6,000 MT, and heavy cruisers, around 8,000 MT, with bigger ordnance for the heavies).
This last is the intriguing Type 055 class, that has a displacement of around 13,000 MT; its predecessor class, the Type 052s, were around 7,500 MT.
So if we look at the Type 052 and its variants, we notice that the original 052 was a maid-of-all-work version, running around hunting submarines, shooting at aircraft and it was hoped attack all surface craft crazy enough to approach the PLAN Grand Fleet. They gradually tinkered with the model, until today, as the 052D, it is more or less the AA platform of choice in a PLAN Task Force. The big brothers, the 055 types, took over the fleet defence against surface vessels, and submarines role rather smoothly.
Do we need to do that ? - 3 hulls at a time, make modifications and changes, freeze requirements, go into bulk production.
Yes and no. That depends on what we have in mind for our Navy. I am not sure that we have worked out what our naval roles under the integrated theatre command Southern Command is going to be. That in turn will depend the equipment, sensors and armaments, and will allow us, after some time spent in assessing different variations, to freeze on one design. So, yes.
There is also a case for no.