That will depends on the 055 class DDG programme's progress, because 052D and 055 carries essentially the same package, alas the latter is a bigger hull that can pack more VLS modules. That said, if the 055 runs into hickups, we might expect more 052D ordered to replace the remainding 051 Luda series.
I think even if 055 is delayed for a year or two, in the medium term, the 055 will definitely become a significant part of the Chinese navy's surface combatant orbat. Whether any short term delay will result in additional 052D production is another question, because that in turn depends on how many 052Ds the Navy may want in the first place. If they were intending to only produce 12, then they might consider it viable to build another 2 to make up the numbers if 055 has any short term delay (which there is no hint of btw).
But if the Navy was intending to procure say, 24 to begin with, then the 052D's production may continuously run up to the early 20s, at which point any short term delays of 055 production (from our point in the present) would long have been resolved anyway, thus not necessitating any 'additional' 052Ds.
Ultimately, the question we need to ask is what will the Chinese Navy's required surface combatant tonnage be -- because in the next few years, as a few more 052Ds enter service, we will reach a point where the oldest destroyers in the Navy will be the pair of 052 class/single 051B class, and they may only end up being retired in the mid 2020s at the earliest.
If we define the modernization process as "replacing identified obsolete ships with modern equivalents on a one for one basis," then within four years it may well be that the Chinese Navy's major surface combatant forces (destroyer and frigate forces) will have completed their modernization process, a process which began in the 1990s.
Therefore next on the list would be to actually determine how large the Chinese Navy will seek to expand, in a numerical basis in terms of the actual number of ships in operation.
Because I have a feeling that they will not rest on their laurels even once all their 24 frontline destroyers and 24 frontline frigates reach a state of relative modernity, and will instead seek to expand the actual number of destroyers and frigates in service beyond legacy numbers.
That is the big unknown.