I think a Truck and Coupe are just too hard. Model X territory. All new body, interiors etc. The cargo van could be a mostly stripped down model X with the expensive windscreen swapped out and simple doors. Then the interior could be done on a sort of ad-hoc final assembly line with much simpler parts. Yeah, not a likely theory but fun to consider. It would be a really efficient way to increase the unit volume and make use of their existing capacity, while addressing an untapped market.
Interesting possibility -- they definitely are thinking of using the X platform for other things (e.g. minibus). Would also fit nicely with getting into the truck business, which they obviously plan to do with Tesla Semi. Still probably wrong but nothing I've heard so far sounds obviously "right" so who knows ....