I bet sarcasm will be difficult to detect by then given linguistic drift. They will likely be thinking "Gazooks! Those people were stupid."
It was interesting to read a properly footnoted play,
Lysistrata. It was written in Greek, well over 2000 years ago. Puns and wordplay don't translate well, across languages or long time periods. And of course, pop culture references don't age well. The footnotes explained that sort of thing.
We've got a ridiculous number of unintuitive phrases or references.
The whole nine yards, up to my eyes in <blank>, "I wouldn't know him from Adam," that's bullshit, you're pulling my leg, three fries short of a Happy Meal - and so on. Try translating that verbatim, and see if someone will understand the context, especially if you try some wordplay.
"Why was that guy pulling on the other person's leg? Was his foot stuck under something? And why does this one character continually reference bovine excrement, even though they are nowhere near a farm?"
Or here we go, from Whose Line, at the end of a lengthy setup: "Only Hugh can prevent florist friars."
It requires knowledge of Playboy, Smokey Bear, and the current pronunciations used in the English language.
It's probably a big part of why Shakespeare just doesn't do anything for me. Bleh, I hated reading that stuff, never did see the big appeal. I bet he was just writing cheap bits of entertainment so that he could pay his bills.
Either way, if just some shred of this forum survives, I nominate NuclearNed's posts, for an idea of our culture, and Rubycon's posts for a record of our technological level.