I think you’re really hung up on that they brought up that Columbus was a shitty person. The joke isn’t even about that. Like you said, it’s well known, it’s the context in which the information is being given that makes it funny.
I don’t know if you’ve ever seen Scrubs, but there’s a scene when a character burst into the scene singing “It’s a Beautiful Morning.” Turns out he’s at a funeral. That isn’t funny because the character sang a song, it’s funny because of where he was singing it and how it’s juxtaposed with where he was. What you’re doing right now is, “so what’s the joke? That it’s a beautiful morning? We already know that! This is woke bullshit!”
If you put that scene up would you cut out the part that involves the funeral?
If I was posting it as a meme? Maybe. I could see myself posting like… “someone waking up at 6 am VS someone already up” and post just the character singing the line. Would I expect everyone to get it? No, not unless I’m posting in a place where 100% of the people are supposed to know the next scene is him at a funeral. But I’d be okay knowing that some people may not get the joke because I didn’t post, “by the way, you see, in this scene, this character is saying ‘it’s a beautiful morning,’ but it is in fact not a beautiful morning! Because he is actually at a funeral, which is so sad! I used this because, while someone who is still awake might enjoy an early morning, someone who is just waking up may not. You see, if you watched the show, you will know the next scene is people looking confused and offended at the funeral. This would be the face of the early riser, would it not! Oh, what a laugh! Please see this link to the full scene and episode, so the joke can really hit you.”
Tons of memes are reduced to their basic parts. That’s just memes. Hell," Loss" is a great example of that. It’s just layout at this point. And sometimes if you don’t see the reference where people sneak it in, you’re just like, “I don’t get it, this just looks like a normal post” and that’s okay. It’s okay not to get the joke.