That wouldn't be A anymore.
The key message of that leak(coupled with the post about lengthening not constituting enough of a change for a new letter) was basically that PLAN needs the line rolling.
We don't know if it's possible with these changes or no, but changing main weapon system is clearly enough for a new mod.
IMHO, HHQ-16 will remain to be a separate existence for lesser warships in foreseeable future.
This is only my theoretical to bridge the gap between the 054A and the 052D systems.
Contrary to what most people's own visions about weapons systems, perhaps the PLAN doesn't really care much about quad pack missiles and it really isn't as high a priority to them as some people might want to be. What I think is high on their list is electronic warfare along with communications.
I don't think there would be much changes at all except for logical changes on the EW, as the 054A carry the unique Type 751 ESM and ECM system which is not found on other PLAN ships. The last four 054A has changes however in the EW system. The Type 751 unit on the upper mast, likely the ESM, have been modified to a new version with what appears to be a crown of elements on top, and the 751 unit on the bottom is replaced by the beefier and ubiquitous Type 726-3 ECM that has become standard throughout the PLAN.
I can imagine the topmost 751 ESM unit to be replaced by 721-1 and -2 ESM systems as part of the PLAN's standardization around the Type 726 electronic warfare suite. The 052, 053H3, 051B and DDG 136/137 refits all feature the Type 726-1, -2, -3, -4, the set of which equips the 052C/D. The 726 EW system continues to evolve, and the Type 075 is the first ship to feature new changes and modifications to the 726 ESM system, or those units can be a new system, and those changes can be passed to future ships.
One of the biggest changes we have seen on the 054A all these years is the growth of SATCOMs on top of the hanger deck. If you take a ship, you can tell if the picture of it is an older one or a more recent one from the growth of the domes at the back. This reflects the explosion of Chinese satellite constellations in the last ten years, and one can imagine what and how the ship is using these satellites. These SATCOMs have been retrofitted into the ships all these years and done in an ad hoc manner, such as the location of one dome isn't the same on another ship, and some ships have different domes than others. The last four 054A also feature a brand new SATCOM array which is also found on the 053H3 refit. With new build 054A, all these mess would have to be standardized, and the SATCOMs will have to be fitted on the ship before it leaves the yard.
One potential change is the Type 364 radar to a new type, like the one you see on the Type 075. The 075 is the first installation of this new radar. If this happens on the 054A, then this new radar can become PLAN's new standard and it may also get fitted on top of the next 052D batch, and become part of the MLU kit for the older ships.