That is certainly true. But I think that this close to the guaranteed cancelation of the stock it may be more likely that any shorter covering is due to them losing the borrow. If the stock they borrowed is, for any number of reasons, no longer available to them, and no other stock is readily available to borrow, they may have to repurchase the stock and deliver it back, which makes it a forced cover.
It doesn't happen nearly as often as pumpers claim it does (MOASS!!!), as there is usually other stock available to borrow. But since almost all of BBBYQ's float is already sold short (and why wouldn't it be considering they will make a guaranteed 100% profit from here), it is very possible that they have just run out of stock to borrow.