All Local files and settings will be erased once the device is Powerwashed.

While most of Chrome OS' files are specific to the user's account there are still some files that are stored locally, and will be permanently deleted once Powerwashed.

Any files that are saved to your devices local drive are often stored in the Downloads folder. This folder should always be backed up to either an external device, or your Google Drive before the Powerwash process.

Any Google Accounts that were previously used on the device will be removed once the device is Powerwashed, along with settings that are associated with the account. These accounts can be rested to the device, given that you have the account information beforehand.

If you intend on turning your device over to a new owner, do not ender your account information once the process it complete.

Powerwashing the device does not remove any enterprise enforced profiles, and does not remove any MDM profiles.