As I understand it, neither of those statements are exactly true. Tesla replaces battery packs and then sends the old one back to the factory to be refurbished

As I understand it, neither of those statements are exactly true. Tesla replaces battery packs and then sends the old one back to the factory to be refurbished, rather than junked. As for future designs, a structural battery pack would still be replaceable. The difference is that the battery pack would supply a portion of the strength and rigidity of the frame. That doesn’t mean the car would fall apart if you removed it, however.