Apple Posts Knowledgebase Article Advising the Deletion of Touch Bar Data Before Selling a MacBook Pro
First, start up from macOS Recovery: Hold down Command-R on your keyboard immediately after pressing the power button to turn on your Mac, or immediately after your Mac begins to restart.
When the macOS Utilities window appears, choose Utilities > Terminal in the menu bar. Type this command in Terminal:
According to Stephen Hackett, this command will wipe recorded fingerprints.
This isn’t a complicated command, but it does feel inelegant. You know how iOS has a button to “erase all content and settings” that you’re supposed to tap before you sell or exchange your iPhone? I feel like MacOS could use one of those, too: it would be great if you could boot into Recovery mode and then click one button to prepare your Mac for sale. It could erase Touch Bar data, remove encryption keys, and do its best to wipe data and make it unrecoverable. It’s a little thing, but the little things matter.