Well we should first establish some sort of contract how to convey the "I feel that I actually understand this particular piece of information, so when confronted with it in the future, you can mark is as such". My lines of thought were more about a tutorial page that would present the same techniques as course you have finished a week prior, or news page reporting on an event you just read about on a different news site a minute before … stuff like this … so you wold potentially save the time skimming/reading/understanding only to realise there was no added value for you in that particular moment. Or while scrolling through a comment section, hide comment parts repeating the same remark, or joke.

Or (and this is actually doable absolutely without any "AI" at all):

    What the bloody hell actually newly appeared on this particular URL since my last visit?

(There is one page nearby that would be quite unusable for me, had I not a crude userscript aid for this particular purpose. But I can imagine having a digest about "What's new here?" / "Noteworthy responses?" would be way better.)

For the "I need to cite this source", naturally, you would want the "verbatim" view without any amendments anyway. Also probably before sharing / directing someone to the resource, looking at the "true form" would be still pretty necessary.