Ok, I think I understand your usage now. Thanks for the explanation. I'm still trying to wrap my head around how that usage came to be. There doesn't seem to be any link to the true definition of the prefix "meta" at all - hence my reason for needing to ask about it.
You're still making quite a few assumptions though (probably why you got offended so easily).
For one; I understand how words can change their meanings over time, and new words get made up. This is generally the result of kids and foreign language speaking immigrants that don't have a very good grasp of the language. I assumed kids in this case.
Secondly; I don't play other card games like this, so using them as an example of why I should know doesn't really work. (My brother has been playing Magic for 20+ years, and I haven't heard him use the term "meta" either).
Also; I have no idea what "moba", "dota" and "smite" are. I was under the impression Yu Gi Oh was like Pokemon.