Blitzo has the correct interpretation of my suggested force structure, i.e. I anticipate this vessel succeeding 056 (which to say succeeding it in production, the two types would of course serve alongside one another for the next ~20yrs), not 054. As a larger vessel this new type -- which for the sake of clarity within my own conceptual scheme I will label a corvette -- would certainly have better range, endurance and seakeeping qualities than 056, enabling it to operate further from shore, potentially displacing frigates from certain "near sea" duties and freeing them for more blue-water taskings, but certainly they would not themselves be "blue water combatants".
My conception of and for the Chinese Navy is of a general "light/medium/heavy" force structure that is carried across generations, reflecting the continuous nature of PLAN's commitments (in contrast to e.g. USA or UK which have very limited commitments close to home, resulting in discontinuous force structure). While this general structure is preserved, the capabilities/range/endurance within each respective category evolves over time according to national resources. The general trend is towards increasing displacement within each category, reflecting both Chinese-specific (i.e. economic growth, technological mastery) and global (i.e. the trend even amongst economically sedate nations for new ships to be larger than those they are replacing) inputs.
Light: 037/022 -> 056 -> Sino-LCS
Medium: 053 -> 054 -> 057
Heavy: 051 -> 052 -> 055
The above structure has several noteworthy implications that bear on other discussions: that I expect 052 production to come to an end rather than continue alongside 055, and that I do not expect a direct replacement for PLAN's remaining small (i.e. <1000 tons) combatants, niches like minesweepers excepted.
Since first arriving at this conceptual model, I have been gratified to observe first the high tempo of 055 construction, which augers against ongoing 052 construction, and now this latest news of a new ~2500-3000 ton design attached to PLAN.
At this point the greatest risks I see for my model are the projections for "up to 70" 056s -- where if this Sino-LCS is to come to fruition one would expect 056 production to come to an end sooner rather than later -- and the dearth of information regarding a future frigate. Of course even if there is a Type 054B that is a fairly modest evolution from the current 054A (i.e. <4500 tons), it could be a transitional type while waiting on a larger, clean-sheet design to emerge.
Alternatively, from a fixed displacement perspective, one could envision this new LCS type as directly replacing 053H1G and 053H3 vessels (total of nineteen currently in service) over the course of the 2020s, with such 054B/057s as are produced seen as pure "expansion".