Oven-canning does not pose a large risk of permanently damaging an oven. There is a considerable likelihood that the jars may explode during the canning process, but this does not cause damage to appliances.
Home canners are strongly advised not to use their ovens to process food for canning. This recommendation is based on concerns about food safety, not about preventing damage to kitchen appliances. Heating jars of food in an oven does not guarantee that the entire contents of the jars reach a temperature sufficient to kill harmful bacteria. Also, the dry heat of the oven can cause jars to explode, causing potential injury.