SRAM on 2N is 11% smaller than on N3 this is very good when we was stuck from 5N on 0.021umThey will do whatever fits their server CPUs best, and 12-core CCDs seem probable. Otherwise you have a sIOD with a giant Infinite Fabric hub with 16+ links to CCDs, which I don't think is optimal.
Regarding node shrinking, what's the SRAM scaling factor in N3 and N2 nodes? If it's bad then 48 MB of L3 and all of L2 will be very costly.