I don't believe at all that a 12-13kt "destroyer" will be produced in the same numbers as a 052C/D/E destroyer. If the 055 is 12-13kt full displacement it will be a true cruiser and will fill a cruiser's role in the PLAN. If the 055 is 9-10kt full displacement it will probably be a 052C/D replacement and there will likely be no 052E, and we may yet look for an even larger displacement cruiser in the PLAN's future.
I agree that the terminology and nomenclature of naval surface ships do not have as much meaning as they once did, and of course any 12-13k ton large destroyer would be called a cruiser. I personally am going to call the 055 a large destroyer because that's how the Chinese language defence forums have called it, but for practical purposes, yes 055 of the expected weight class would essentially be a cruiser.
But the question that arises, is why is it judged unlikely for the Chinese Navy to build a similar or slightly smaller of large destroyers/cruisers to medium destroyers?