They probably got burned so bad by the Sick. Ohh Furds they blamed it on diesel platforms instead of understanding that it was Furd and Navistar that burned them.
Their fuel costs will be higher and their maintenance costs will be pretty steep replacing engines and transmissions. I don't think the gasser GMs engines or transmissions will hold up very well with all the weight of an ambulance, equipment, crew, and victim to haul around at high speed and idle for long periods.
Its too bad buyers and decision makers weren't wise enough to buy new Ram 4500s or 5500s.