I have a 2019 Macbook Pro 13 inch, and the touch bar flashes and flickers, usually shortly after awaking from sleep. This phenomenon persists even after factory resetting of the computer and/or OS reinstall (incl. Ventura, Monterey, Catalina, and Mojave), and/or NVRAM/SMC reset.
HW automatic testing came out flawless from a professional Apple Service Provider.