As often happens with Apple, there is a great deal more fuss than the issue deserves.
It affects pretty much every LCD tablet with a low refresh rate of 60Hz or less. It is typically more pronounced in one view over the other, due to the direction the video lines refresh. The iPad Mini 6 shows it in portrait view. The current iPad and iPad Mini 5 shows it in landscape view. It is easier to spot in portrait, due to the long vertical view. Someone saw this, posted what they were convinced was a big new flaw in an “APPLE” product. Most of the other news and videos are people telling everyone that, “yes it exists”, and “no, it’s not a new thing”.