The relative capability of the 054A's sensor suite is already known to me, there's no need to express it in such extensive detail.
If you are saying that you think the new batch of 054As should field a more modern sensor suite, I don't have any disagreement with you inherently, and on balance I think it is plausible that the Sea Eagle might be replaced with a small sized AESA, perhaps the same one fitted to Pakistani 054APs.
But at the same time, the only reason I can see the PLA procuring 20 054As while 054B will be ongoing at the same time, is if they want the extra 054A hulls in service quickly and without hassle.
Whether that means they will tolerate a degree of modification to the sensor suite is not something I can say at this stage, but it depends on how the PLAN assesses the relative risk.
I will say that these ships are of course going to be in service for decades, but also there's no reason an MLU has to be that urgent such that they have to be introduced with these 20 ships in particular.
It would be nice if they were, but if it means taking more years to get these 20 ships in service, would the PLAN deem the timing of these improvements worth it?
Again, let me reiterate that I fully appreciate the technology where 054A's sensor suite sits relative to various global peers (or even other ships in the Chinese Navy). I also fully agree and expect that the PLAN's 054A fleet will get a sensor MLU in the not too distant future.
But I'm arguing whether it is important for these 20 ships in particular to be the ones to field these upgrades.
I don't know why you would think that a new sensor suite would delay the building of 054A. They are the last things that are fitted on the ship, and it is likely the trials for the Type 382 replacement has already been finished some time ago. Solid state, modular AESA radars are physically simpler, and they can be made lighter as you can eliminate the need of a heavy cavity based electron tube. As rotating AESA, its likely these are air cooled. We are not aiming for the best possible performance here, just good enough to allow for a light air cooled rotary radar. If the new radar is designed as a plug in replacement to the Type 382, it would be made to match the Type 382's sitting weight and power requirements as part of its required specification. Likewise for a radar that is meant as the Type 364 replacement. This means you don't need any changes on the 054A hull, frame and superstructure, as well as power systems and so on. Everything is as is, because the new sensors are designed to fit the ship, not the other way around.
The problem I see about installing the older Type 382 is that it may force you to upgrade the ship soon anyway, putting the ship out of service, and you add the cost of the new radar and installation of the new system. This sounds to me, a significant extra expanse that you don't have to make if you do it right the first time.
Even if you wish to retain the Type 382, at least the Type 364 should be changed, and with already two installations via the two 075, the Seagull-C replacement itself is already a low risk and bureaucratically certified tool. The current Type 364 radar is mainly a 2D radar, it only tracks and provide information via the horizontal axis, with its update rate mechanically tied to its rotational rate per minute. Changing this to a 3D dual side, not only doubles the rate of scan, the speed of electronic scanning means its also possible have an X number of scans while the target is within the arc of the face. This radar also overlaps into what the Type 382 does, so it can even mitigate the Sea Eagle's disadvantages since the ship at least has one potential LPI capable radar. In LPI mode, you don't have to use the Type 382, you only have to use this dual sided AESA.
As for using the radar that's on the PN 054A/P, also used on the BN's C13B, that's also a possibility. This SR2410C might even be used along with the Seagull-C replacement. And maybe, maybe, it can be used in future batches of the 056A. Maybe maybe used with the MLU of the 054 and the 052B, unless Type 382's have been ordered long ago and the MLU kits are already sitting in some warehouse out there.
The body language of having the 054A and 054B being built in parallel and overlap could suggest the 054B being a more radical design, and that could mean for me the possibility of having the 055's X-band AESAs is once again an increased likelihood on this ship.
Finally I would assume there is some institutional resistance to bring back a ship that is already four years out of production and on the edge of obsolete, and there must be something the designers and engineers must present to the PLA brass to convince them to build another 20 instead of let's say, build more 052DLs.