Are we sure another batch of 20 054As have been ordered? Tbh that doesn't make sense to me, if the 054B has been delayed somehow and this is another interim order you'd think it'd be smaller, like under 10. Despite the huge numbers that have been built the main thing the 054A has going for it is okay anti-air ability (and anti-submarine?), and even then only medium-range SAMs, it's weak in other areas like anti-ship and nonexistent land-attack capability. Overall clearly less capable than something like the Admiral Gorshkov class for instance and far less impressive than the PLAN's new destroyer classes in stark contrast. You'd think China should wait until the 054B before ordering more?
Is it possible the new order is actually for an upgraded class?
To be clear, this is what I think is happening.
The PLAN reserved 20
slots for frigates, and another 20 slots for destroyers in other shipyards which will be another story. The orders were for 054A, but they don't necessarily be like the 054A we have seen before. I counted at least a total of four batches or flights of 054A, and this is the fifth one, which on top of the fourth, which alone has many changes away from the first, added AESA target illuminators for the missiles replacing the AJK-16 illuminators. Its possible the next batch of ships may have more changes --- the minimum sized batch we have seen for the 054A is four, with the first four (1st to 4th) and the last four (26th to 30th) are separate batches of their own, with differing features.
The nature of the shipbuilding business is that the customer has to make orders in advance to reserve the building slots. That's what the PLAN has to do. But it does not mean that the last ship made will be the same as the first, and as we have seen with many other ship classes, there are always gradual changes along the way. The customer, in which case the PLAN, can always modify the contract. For example, recently, the order for the Evergreen A class on Jiangnan Shipyards called originally for 23,888 TEU or something. But Evergreen modified their contract so that the ships, which already one has launched, is now over 24,000 TEU.
In short, what is set is stone is that you're going to have 20 additional frigates. What is not set in stone is all the modifications and upgrades to them. This includes the option to switch the remaining reserved 054A to the 054B if they do desire.