It seems like just in time to replenish a consciously sized inventory, rather than just in time to get a bolt on to the assembly line, would be a sensible arrangement.

Sizing of the inventory would be based on how long you've decided you need to operate if all inputs stop. So maybe they "just" need to increase that sizing, rather than effectively relying on the delivering semi trucks for inventory storage.

I drive a semi truck, and sometimes a trip will be designated JIT, with a note that being late may halt production. Quite often these trips are to deliver tires to a distributor, and not, say, to a car builder. And I often think "Really?" Followed by "OK, whatever."