Bulbapedia uses the information given through official sources above information generated by unofficial sources. CoroCoro an official source, while you are not. Unless an official Japanese source says that the romanization "Zoroa" is correct, its romanized name as far as Bulbapedia is concerned, is Zorua.
The page will stay at Zorua (Pokémon) unless such events happen, or until its official English name is revealed. End of story.