I wouldn't buy a pre-owned model simply because of the battery issue. I haven't checked into it, but I seriously doubt that a dealership is going to replace the battery. Surely that would be cost prohibitive.
I'm happy to buy a used EV in certain circumstances. Some people trade their vehicles in often, because they like to have the latest features. Some drivers regret going electric, so they trade it in for a gas-powered vehicle. Basically, I'd buy a used one in situations where the battery is likely preserved.