"Fight!" mission excluding Final Boss Veigar in requirements?? Why???

In the new Arcade event, one of the missions, "Fight!", requires you play 5 matchmade games with either an Arcade skin or a Battle Boss skin.

When playing a game with the Final Boss skin, after finishing it I noticed the game didn't count towards the main requirements, but instead counted for the alternative one, which was to play 10 normal games, with any skin.

Why is that???

I suppose the Final Boss skin is unique in that he doesn't have the Arcade or the Battle Boss title, but when looking at the skin in the collection tab, it does show he's part of the Arcade: Battle Bosses group of skins!!

What's the reasoning behind him being left out? He is the big bad after all.

Please add him if possible, I hope this is just a dumb mistake on your part and not intentional.

[sg-janna]