I see people misusing words like "canon" and "semi-canon" a lot, so here's a proposal of some definitions. I put them on the wiki. Tell me what you think!
Canon - http://www.mylionking.com/wiki/Canon
Official - http://www.mylionking.com/wiki/Official
Semi-canon/Sub-canon - That which is official but not canon.
Unofficial - http://www.mylionking.com/wiki/Unofficial
Fanon - http://www.mylionking.com/wiki/Fanon
Diagram of how these definitions fit for the characters in The Lion King Universe:

What are you trying to prove exactly? Kopa is just as "real" as Simba or anyone else in the series. That's not what is being argued. What's being argued is whether or not he's unofficial or sub-canon.