I think the point is that regardless of the facts, the general perception is that EV batteries will need to be replaced, and it will be expensive to do so (to the extent that it's uneconomic compared to the car's value). Unless this perception changes, then it will have a negative effect on an older EV's resale value.
This will probably end up being a moot point anyway. In the future, it will be something like manufacturers only providing software updates to a car's OS for x years that kills cars.
Furthermore, I will spontaneously invent an EV vs. hydroen fuel cell battle for supremecy. In that battle, sre EVs VHS or Betamax?