you don't need leverage for a squeeze to happen, leveraging just magnifies the effect. follow me here: "Everyone can't get rich". this is a zero-sum game. if everyone is out of usd, the price will stall and someone will get spooked. some profit-taking will happen and the coins will move to 'stronger' hands. unless the buying pressure is strong, the price will settle at a lower point. long squeeze.
My impression was that "squeeze" specifically meant the effect of margin positions getting liquidated by a big move, necessitating market action by the margin lenders to recover their principal, leading to a multiplication of the move.
It seems I was mistaken!