What probably happened is the mold for the old shell wore out and they had to make a new mold. The molds can be easily damaged if not handled correctly and don't last forever even if they are handled with care. When they changed the mold (for whatever reason), the casing appearance changed a bit. They report it because they don't want to hear people complaining that they think they got a counterfeit card.
If the old mold DIDN'T fail, then I see reason to complain that instead of wasting time with a new casing construction, they should continue to concentrate on updates, which we're a little overdue for at this point and they have been so diligent at providing up to this point.
If a new R4DS is in the works, I worry that updates for the current one will fall by the wayside.
At any rate, it does look like the microSD has been moved to the side of the cart.