I’ve recently updated to tvOS 13.3.
I know if I tap the trackpad while viewing content I will see a display at the bottom of the image showing time viewed and time remaining.
I don’t know if the following is new in 13.3 or just something I stumbled upon for the first time…
If I tap a second time before the display goes away the display changes to the current time and the time the content will end (end of program, whatever).
So far that’s all I’ve noticed in 13.3 that I had not seen before.