Not really, Steam will refund the buyers, ban the seller, and keep the developer fee they paid. Scammers will be down $100 and everyone else will go on like nothing happened.
Other than mobile games or Lego versions, there hasnt been a proper Harry Potter game since 13 years ago and from memory they were extremely average movie tie in games.
Its not a series like Pokemon or Zelda that sees frequent releases. It being the first real game, and done beautifully (graphics/ recreation wise) is certainly the biggest selling point.