irony is a rhetorical device, literary technique, or situation in which there is a sharp incongruity or discordance that goes beyond the simple and evident intention of words or actions. There is presently no accepted method for textually indicating irony,
...basically it just means something surprising.
Good job quoting Wikipedia word for word, however you have totally misunderstood what they're saying. There is
no symbol to indicate irony such as a question mark denotes a question and an exclamation mark denotes yelling or importance, etc. Irony is conveyed through story and not through punctuation.
Let me write you an ironic sentence:
I put a new car alarm in my car so that it wouldn't get stolen. However, when someone tried to pull the handle, the alarm shorted out and unlocked the car. My security system helped the criminal steal my car.
That's irony, and there's dramatic irony where you know about something negative that the other person (or character) doesn't. A perfect example is we know Oedpius is a self-fulfilling prophecy, however he does not; be believes he is doing everything perfectly to avoid his fate. Only we, the readers, know.
Let me write you a non-ironic sentence:
Me and my brother went out to buy new shoes. We ended up buying the same shoes.
That is called a coincidence, so as the point of this topic is it's a coincidence that v21 is coming out the year the world apparently ends on the 21st.
It would be ironic if Kompressor and Badspot released v21 on the 21st to stop the world from ending, but they actually blew up the world with it.
The two things containing the same number is a
coincidence.