I don't think AMD are increasing the numbers of cores per chiplet instead of just increasing the number of chiplets.
They are getting new IOD for sure, as current one is dragging them down with power use.
12Cx8 or 8Cx12 is impossible to know yet? We had real good leak for ZEN3 CCX size very early on, do we have anything on ZEN4 ?
I think it is in AMD's best interest to continue to rise CCX size, as their main competition is going to be not Intel, but ARM monolith monsters on same 5nm process in 2022.
For example SiPearl is 72 core monolith, supposedly with (ARM claims for V1) 50% ST performance uplift versus N1 on 7nm? Can someone fit 96C on 5nm?