Even if it turns out that GME can be short squeezed until there is not a single share shorted anymore, the retail investors will then collectively be HODLing a ton of stock in a company losing hundreds of millions per year. Buying pressure for such stocks is typically low. There is no way everyone can get out at the top, so a lot of people will have to sell at very low prices. This is even true if the original thesis of "we can pump this stock to $1000" is true.