Finally, someone who shares my feelings about Arcanine :'D He WILL have a Mega for sure.
Also, in the pokedex entries for first and second gen, his description is: Yellow: A legendary Pokémon in China. Many people are charmed by its grace and beauty while running. Gold: This legendary Chinese Pokémon is considered magnificent. Many people are enchanted by its grand mane.
Also, what was stated above about Moltres taking his spot in the trio is true. Idk where to get you the exact info though.
"Something big is about to happen here...which means one thing...IT HAS NOTHING TO DO WITH ME!"