It is generally not recommended to reuse pans that were left in the oven during a self-clean cycle. The high temperatures used during the self-clean cycle can reach upwards of 900 degrees Fahrenheit (482 degrees Celsius), which can cause any residual oils, food particles, or grease on the pans to burn and turn into ash.
While the self-clean cycle is designed to burn off and remove built-up grime and residue from the oven, it can also affect other items left inside, including pans. The extreme heat can potentially damage the finish, non-stick coating, or any other protective coatings on the pans. It may also alter the properties of the metal itself, leading to warping or other structural issues.
To avoid potential damage or health risks, it is best to remove all pans, bakeware, and other items from the oven before running a self-clean cycle. If you accidentally left pans inside during the cleaning process, it is advisable to inspect them carefully for any signs of damage, warping, or coating degradation. If in doubt, it is generally safer to err on the side of caution and replace the pans rather than risk using damaged or compromised cookware.