Why not 5+5? They use 3+3 for 6 core chips.Might be a niche SKU with more cache, I'm curious what's the die config for it, 6+4 or 3+3+2+2/4+2+2+2 or maybe some weird 4+4+2? Can't see them using more than 2 dies for a lower priced SKU though, so I think 6+4 is the most likely config.
Regardless, I just cannot fathom how they would increase CCX density without it being a 7nm chip and those will certainly not be production ready by the time the 9th generation Intel chips are released.