Correct. The point here is to make the stock illiquid in that buyers can't find shares to purchase, and sellers refuse to sell. The willingness to short decreases when they are unable to buy shares back. When they short more to pummel the PPS, they are trying to induce a panic. When they can't induce one, they let the price run by shorting less, and induce a profit taking sell-off. Plus, they can short more and re-pummel it. They are strategic at breaking the resolve of the holders. But if all that doesn't work? They end up more in the hole.
I personally don't believe we're seeing any squeezes just yet. Although I don't know the specifics of the whole mechanism, I believe that when the squeeze starts, you will be unable to purchase shares. Buy orders simply won't go through. Shorting will have stopped, no one is selling, and everyone is trying to buy. However, we are seeing major accumulation. In EIGH alone recently, it would appear that somewhere between 20-40 million more shares are locked up tight. From the posts I'm seeing, people are still able to purchase shares. The good thing is that the strength increases immensely every time one of these accumulation phases happen.