I think you might be confusing two different thing

I think you might be confusing two different things.
If they already shorted shares that means the shares were sold, meaning the borrowed shares or the naked fictional short shares were sold. And, they eventually must buy the shares back at some point.
If they merely borrowed the shares and holding them for later, that is something different meaning they are holding them to short now or later.
But, if they are currently short shares right now it benefits them none to wait for the price to go up, at least as to the short shares.
Let's say they shorted at $4, and the price is now $5, that means the short is upside down by $1 per share. If they cover now, they only lose $1 per share. But, if they wait to $20 per share, they are then upside down $16 per share!
If they are shorting the held borrowed shares at $20, those are different shares than those that were already shorted.
So, no that is not why we haven't seen many cover yet.
Why they have not covered is anyone's guess. Maybe they are in too deep and hoping for a miracle.