I am not an expert but from the info I could find (outside of discussion boards) there is no obligation for shorts to cover after a split. However, the scarcity of shares (in absolute numbers) plus the fact that we will likely move upwards with nasdaq uplisting & other great news, mean that we could very well have a "normal" short squeeze just due to the fact that shorts will be scared...

as of the possibility for them to keep it forever as paper loss instead of covering... I don't know. I guess everything is possible in the wild world of stock markets