There's not a single "deadline", each short seller has their own contract with their own terms and conditions.
So since it's a rotating cast of characters, it is entirely possible that the very early short position holders have all taken their lumps, and the current short sellers sold their borrowed shares for $100's of dollars each, and now have the ability to hold on for quite some time.
Sure and also the short options themselves have a price tag. That cannot be very good for an option against a stock in that state.
Also I think this is being over-analyzed. Reading the comments the majority of users there don't claim they really know all the details. To me this is a protest against hedge funds.
Ironically, in their attempt to protest hedge funds, they have probably handed over large amounts of money to hedge funds. Sure, the funds that got slammed by the short squeeze were hurt, but as more redditors started piling in to buy shares and buy options, other hedge funds took advantage of the situation. Who do the WSB crowd think is selling them shares or call options at this point?
So since it's a rotating cast of characters, it is entirely possible that the very early short position holders have all taken their lumps, and the current short sellers sold their borrowed shares for $100's of dollars each, and now have the ability to hold on for quite some time.