Hubs create that pretty heat map of potential supply, but there aren't any supplies constantly distributed if there's no one there to consume them. The colors are the strength of the supply field, as it were, not a measure of crates being heedlessly dumped in the middle of nowhere each day.
You sure? If you motorise a hub and there's no troops to use the supply, I'm pretty sure you still lose trucks. Then again, maybe that's tied to a fixed attrition rate that always gets applied when you motorise a hub.