That's confusing and doesn't make much sense to me.
We haven't even seen a single LHD launched, let alone operated by PLAN. Now they're designing a second, larger class of LHD? Why is this presumed second LHD so closely following the first one? Since PLAN has never operated any LHD, one would think that it at least takes some time for PLAN to operate it before the experience is incorporated into the design of the next generation. LHD is not that difficult to build, compared with some of China's other combat ships. If tonnage is the reason for the second class, why not start with the 40k class from the beginning? Why the need of the 30k class LHD to begin with?
There are so many holes in this rumor; it can hardly be called credible.
it's not entirely illogical -- for example, I'm sure that plans and designs for 003 were worked on before Liaoning entered service. Planning ahead for a larger and more capable design before the first of a type is complete isn't out of the question. I would argue the PLAN's operation of 071 and Liaoning provides a respectable basis to make some informed decisions regarding what they want out of their LHD as well.
as for starting with the 30k ton class, it could have been a case of conservatism at the time when the decision was made, but requirements and/or confidence had since changed, but it may also be too late to scrap the 30k ton class LHDs that have already been worked on.
this isn't to say I believe the rumour but I think it isn't crazy by any stretch