There's been hundreds of videos and posts about this already, and for some reason, it's not recognized as an actual fault or issue.

This issue is happening with MacBook Pro users from 2016 through the 2019 models.

I have a 2019 13 Inch MacBook Pro with the TouchBar. If I do not use the laptop for about 60-75 seconds, the touch-bar dims (60 seconds) and in 75 seconds it switches off (presumably to prevent OLED burn-in).

This is normal, but recently a bright white rectangle in the top right corner starts flashing out of nowhere and continues to do so until I touch it, after which everything goes back to normal.

I have found a solution to this dreaded TouchBar Flickering. This may work in solving the Flickering issue.

You need to refresh your Touch Bar:

Go to Activity Monitor on your Mac- search for 'TouchBar Server' and quit it by clicking on the 'x' on the top left. Also, quit 'Control Strip'.

There is also a shortcut to perform these tasks from the terminal.

Copy & paste:

sudo pkill TouchBarServer

Refresh the Control Strip in Touch Bar, copy & paste:

killall ControlStrip

This immediately stopped the flickering for me.  Doesn't really seem to be a hardware issue.