Yes. However, the seller wants to factory reset it anyway to avoid leaking data, and the buyer wants to factory reset it anyway to ensure the device isn't e.g. saving iCloud backups to the previous owner's account, or doesn't have some weird malware installed (iOS is pretty good at isolating apps, but not perfect, and also jailbreaks exist). So it makes it more important to wipe the device, because attacks are easier, but it's not introducing a fundamentally new requirement.