Offscreen Inertia is a philosophical statement that what you last saw a character do is what they continue to do, even if you never see them again. A movie ends on a Big Damn Kiss and that makes it a Happy Ending because it doesn't suggest any relationship hurdles afterwards. The Bolivian Army Ending isn't a Downer Ending because we never see the characters die, it's always just before. The inspiration of the trope came from The Far Side where a jokey panel showed dogs playing tetherball except the ball was a cat with a rope tied to it, titled "Tethercat" and the artist said it was his most controversial comic ever and he theorized it was because the dogs never stop playing tethercat, you come upon the comic again years later and they are still playing.
The idea is too omnipresent for "straight" examples so it is about examples that intentionally dance around the idea. An episode ends on a character doomed to wander a maze forever, years later the character returns having just now managed to escape the maze. But because it is philosophical rather than a hard trope you will see fan theories bleed in more than others.
Comics are just words and pictures. You can do anything with words and pictures.
Specifically, Tethercat Principle was the former trope name and remains a redirect.

There were a few examples in Offscreen Inertia that bothered me. I was planning to post them in the "Is this an example?" thread, when I realise that I don't actually know what this trope is for, so now every example seems off.
The page is not indexed in Audience Reactions, yet many examples seem to be just that. Most of them amount to "there was a long break between releases so fans were left wondering about characters' cliffhangers". Others are Brick Jokes about characters still being in the same situation they were last seen. Others overlap with Something We Forgot, What Happened to the Mouse?, Bolivian Army Ending and Cut Short.
In summary, I don't get the point of this trope. Is it about audiences believing that a character/event hasn't changed offscreen, or about works referencing such expectations?