Nope - won't be of same design.
There will be a 7 & 8 car version.
I believe the 7 car version will have the C-stock style seating, and the Met having a mix between A-stock & C-stock seating... transverse one side, longdidtudal the other..
Since when? Where did you find this out? The chaps at LUL Upgrades don't know that.
They will both have the same seating, a mix of seating, more or less as shown in the picture further above. I was at a meeting the other day and it was confirmed. The only difference between the Met and the District, C&H lines will be the train length.