With the obvious caveat that any speculation about the future brings: It is part of popular internet culture, and thus will be studied by historians interested in reconstructing or understanding this aspect of our culture, insofar as records of that remain. Dead and missing links are a serious problem in academic literature already, it will be interesting to see how such fleeting things can or will get archived. Beyond that, the level of speculation increases to blind guessing, and that's far beyond what this subreddit is for.

But to give you an example from the past:

We study a lot of fleeting and seemingly 'uniportant' stuff from ancient times, like graffiti or scratches on Roman walls which are not more or less sophisticated than the stuff that gets scribbled or drawn on modern toilet walls. But it is a subject of serious study. Here is a collection of some of them.

I doubt there will be museums solely dedicated to the stuff, but memes will be useful historical records. They show humour, they are a part of popular life, they often show individual problems and individual accounts which are interesting and useful. What was frustrating to 21st century people? What did they feel made them successful? How did they express themselves? Like how something as small as a funny doodle on a Victorian exercise book can be an insight into the lives of Victorians, a meme can be an insight into the lives of people now. Why are memes so attractive? Did memes go in and out of favour? Why were certain memes popular and others not? What makes a meme popular? What section of the population used memes? How much work did it take to make memes?

As for rick rolling, although it could well be lost to history, that could be interesting as well, but probably not just on its own. Why do humans find misdirection funny? Do they find it funny when it is done to themselves as well as other people? Rickrolling could be a part of the history of humour, I suppose.