What makes you think that 16 cores will be mainstream consumer by then? Hell six cores are only now mainstream consumer for new mid-range systems.I think by 20/21 we will be on 16 cores mainstream, also with igpu to worry about, I would hope by then Tripple channel is a go.
What is the feasibility of a crystalwell type L4 cache? On 7nm this has to be feasible for 6 core/16CU APU's does it not?
Alongside quad channel lpddr5 option.