Unprecedented sarcasm is usually unidentifiable.
Of all types of humor, sarcasm can be the most difficult to detect. In fact, the more undetectable it seems, the funnier it is. Or I could say, the more obvious it is the less humorous it is.
Because of this, much relies on a knowledge of the person using the sarcasm. If a friend, with a straight face, says something that is clearly opposite of what they believe, know, understand, etc, it is apparent to me that they are using sarcasm. I’m able to appreciate the humor of what they are saying. If they use sarcasm regularly, I am expecting it and know they are joking. The closer the friend, the more subtle their sarcasm can be.
The problem arises when someone who never uses this form of humor attempts to do so. You don’t expect it, and the time spent discerning if they are serious or not can kill the laughter. It’s likely to be taken seriously, at best as unfunny, and at worst can cause offense.
No point to be made here (other than sarcasm should be used discerningly, carefully and innocuously), just an observation from late-night ruminations.