It may be the same point as 054AGs.
076 apparently shares a lot of equipment with 054B(on top of 003), and it may simply not be ready yet.
Fair point.
However, given that Hudong-Zhonghua is the only shipyard building LHDs for the PLAN, and that there's only one drydock in Hudong-Zhonghua that is large enough to enable LHD construction (there may be two in the future) - The slots available for LHD construction would been pretty tight.
This is yet to include the costs, time and efforts involved in building and operating LHDs versus those of FFGs.
Of course, given that we've seen how quick the 4th 075's construction can be (from seeing hull modules to launching), and borrowing the experience of Fujian's lengthy post-launch fitting out and mooring trials before she's ready for sea trials - Theoretically speaking, there might be a long enough period of time in between the point right after the 1st 076 LHD's launch and before the point of verification of the 076 LHD's final design is completed that would permit the construction of subsequent 076 LHD units, where the construction of a 5th 075 LHD is possible.
Of course, this also depends on whether Hudong-Zhonghua plans to build civilian ships (e.g. LNG tankers), one or more 071 LPDs, or multiple units of FFGs simultaneously right in that drydock within that period of time.
(As a personal sidenote:
Honestly, Guangzhou Shipyard (which've built AORs and AOEs) should really start picking up the slacks of building LPDs and LHDs as well. Can't risk losing LPD-&-LHD-construction capability in case something bad happens to Hudong-Zhonghua.)