Yes, but the characters still retain the essence of who they are in the original stories. Snow White may be tougher- but she is still a beautiful young woman who is essentially good. Rumple didn’t have a love interest before- or a back story- but his personality echoes back to his original story.
Even if they did decide to take liberties with the Wizard of Oz story and make Oz young and smart and out of character, I think having August be the Wizard would be silly and wouldn’t fit in with the show at all. I don’t think the writers would pull something out of the blue like that. It just doesn’t make sense that a character who knows that the book is real and knows that he needs to get Emma to believe is actually someone who has no reason to be involved at all at this point.
If August is Pinocchio, he is a Pinocchio who left fairy tale world and grew up in our world so it makes sense that he might wear a leather jacket and ride a motorcycle. He still has some core traits of the character- insisting he doesn’t lie even though he does on occasion and talking about having faith and believing, all very much a part of the Pinocchio story.