The fact that this will be super-flippable will counter that quite a bit. Even if you have second thoughts about buying a giant truck for $70k, the knowledge that you can turn around and sell it for $75-80k+ makes it a lot more palatable.
Take rate ultimately hinges on like-ability of the truck. If early buyers love the truck demand will grow and the take rate will stay high. If it’s a bit of a disappointment, then the reverse will happen. If Tesla delivers anything near what they promised, take rate will not be an issue at all.