Resetting factory default will not delete anything from the web, it will only wipe the device clean and restore it to "new" state with regard to the software on it. I don't have an iPod or an iCloud account so I can only give you some general guidance: if the iCloud account is based upon your iCloud userID then the userID previously used with the device would no longer be associated with the device. (I expect that this is the case otherwise the iCloud service wouldn't be able to sync across multiple devices.)