I agree that higher power, light weight, compact on board chargers would/could arguably be a big leap forward for range without blowing the cost. Battery capacity can creep up with tech improvements and price declines, Being involved in PV, one thing I can tell you is our industry is starting to slowly move away from high voltage DC, despite the efficiencies. The reason is safety - HV DC can arc long distances and causes very fast very hot fires.
Because I'm PV obsessed, I would vote for the high power charger to be b-directional. It would add very little additional cost (if any) and allow the bike to serve as a home storage system really economically, avoiding the need for additional stuff in the home. This instantly creates a whole new appeal to the growing market of millions of home solar owners because they can smear the cost of bike ownership and storage cost across two devices.