I had no idea TVS did that nor, in the case of digital TVS, can I see any reason why they would do that.
You store the picture in memory, every f****ng 24 bit pixel, and in general you dont blank the screen ever.
You may not even refresh pixels on the screen that are the same as the last time you looked.
Running a full refresh every ~10ms is a very crap way to do it cheaply. And even then even the polarity switch to avoid screen burn wont give you a very pronounced flicker - because you are simply setting the pixel to be the same value using opposite voltage..AIUI.
In all cases flicker is massively less than - say - a CRT screen where the phosphor has to decay fast enough to go dark by itself when its switched off.
LCDS are *actively* switched off.