Now what would a Pikachu do to get a phone number? Maybe Coronis is hiding something, but we shouldn't jump to conclusions.Is Surge ever absent from his gym?
Because if he's always in his gym, then that means you must get his number from someone other than him.
Also, from what Coronis said about the English Pika from Surge, didn't it sound like he knew something but wasn't telling Serebii? Maybe getting his number has to do with Pikachu?