This was one of my thoughts on another thread. As we know in LOS cars in general hold their value mainly because they keep going, with an EV, the battery is the "engine", which most, at this stage, only has a 100,000mile guarantee, if a car has near or over that, who is going to take the gamble, and what will its value be, for sure not the same as a petrol ride.
But, perhaps the savings made from petrol over a period of years will not bother an EV owner or resale value.