Why Henry K. says there will be at least 26 052D, don't see it anywhere else.
I think it's extremely unlikely that China would keep producing large numbers of 052D hulls after production of 055 has been launched. Despite a big difference in size, these ships clearly have a very similar role, as the both are multi-role general purpose destroyers, even more so than of any the older Chinese designs.
It might make some sense to continue producing the smaller (and cheaper) 052D along with the bigger 055 as a kind of hi/lo mix, but this doesn't make much sense because the 055 design seems to be much more advanced in terms of sensors, RCS reduction and even construction techniques, so it probably offers much more value for money, even if it's larger size makes it more expensive to produce.
Of course, it China could choose to develop "052E" that would integrate the advances of 055 design into the hull of 052D and, if they choose to continue producing 052 line, this is what they will almost certainly do.
On the other hand, producing a large frigate (that would be somewhere between 054A and 052D in terms of size and capacity) would, in my opinion, make much more sense.