At this point I'm not sure if the WSB anticipated short squeeze is going to happen, or maybe it has happened already last week.
For whatever it's worth, https://en.wikipedia.org/wiki/GameStop_short_squeeze says it definitely happened, but at the same time it offers zero sources for its claim that "the rush to buy shares to cover those positions as the price rose caused it to rise even further".
Furthermore, has anyone actually demonstrated Melvin actually shorted the stock? It would seem like they owned a few puts. Puts don't get squeezed, they just expire out of the money.