I have been a fan of hydrogen powered vehicles for a long time, as they have many advantages over pure electric in most all applications except in "city/short trip" areas.
In the basic premise, hydrogen fuel cell vehicles are just electric one with batteries replaced with fuel cells and hydrogen storage. Making the fuel is a closed loop and clean process with renewable electric sources like solar or wind and lets those sources store the energy if no other loads so the utilization can be 100%.
I think the whole idea of battery powered even 10-12K# class b's would need a lot better and faster charging batteries that are probably not going to be around in the time hydrogen could be rolled out. Trying to match the 3-500 mile range between fuel stops and 10 minute refills will tough unless the battery packs are huge and rapid change instead of charging while you wait. We may not be typical class b users, as we tend to do fairly long drives to get where we are going, and then stay there a while. 2-3 fillup days are typical for us so long times at chargers would not work well.
I hope the startup does well, and quickly.