I don't buy it. It's easier to make this argument for companies that are building their own hardware, since they know it can be immediately used. OpenAI's move is tantamount to hoarding for the sake of strangling competition. There was plenty of supply to allow for their plans without this move (especially since they will probably go bankrupt at this rate).
How exactly could they 'hoard' this? There's no place in the world to store that much undiced wafer. It will all go bad.