Canon = official is true but it doesn't work that simply. You see, TLK book universe includes many books which contents contradict each others--including the Kopa books' contents. Yet all the books are equally official in the TLK universe. But of course they can't all be canon or even semi-canon because they contradict each others. And you can not just pick and choose and claim it official semi-canon/canon. Because why should your preference be it any more than any of the other official books' content?
Hence, canon means more than just official.
Canon = the most official source in the fandom. In this case the first film.
[quote="QueenSummer"]Kopa is either canon or semi-canon.[/quote]
Well, rather semi-canon than canon. But I can't see him as even semi-canon because in my logic, semi-canon is something that has been approved and then tied into the actual canon by the actual canon's makers (in this case the films' makers, ultimately the first film's.) Because how else could that something carry the term 'canon' in it?
So, I think the most accurate term for Kopa's status in TLK universe when regarding the movies, is semi-official--because what the movies literally show and say and whatever their makers say are the most official source in the entity of TLK universe. =)