to me , a truck is a vehicle designed to perform "work"...a tool... a machine, whose form itself, is dictated by the commercial duties it was created to carry out. Any other uses are a "bonus". The white Ford Van is a truck, if it never carries a paint brush. Minivans are family/people movers..."minivans"... no matter, what they are used for.
Would appear, your local DOT has the final and ultimate(financial)say. I don't think these vehicles any more "truck" than a Wrangler.