their names on the lease with me
Which implies that all 4 of you signed the same lease instead of separate leases in each name.
That means that any one of you is responsible for the debt if the other 3 bail.
If the LL takes this to court, do I have any chance of not having to split the extra 1000 dollars that my roomates did not pay?
Drew answered that question. You're on the hook for the whole thing if the others don't pay. Doesn't matter how much you paid already.
The LL is saying he wants to file this in court on the 5th of December, none of the former roomates respond to him,
No surprise there.
he will not work with me to avoid pursuing me for the money they owe.
No surprise there either.
I would just hope that maybe the court would stand up for me if I can show that I have already paid my entire share of what should have been owed.
No, the court won't stand up for you.
In the end, there will be a judgment against you that will follow you around for many years and subject you to all sorts of unpleasant consequences.
If you want to avoid that I suggest you find a way to pay what is owed and then sue your roommates for indemnification.
If you can't collect, you chalk it up to tuition for a life lesson from school of hard knocks.
Avoid roommate arrangements in the future. Wouldn't kill you to live in a small efficiency apartment that you can afford on your own.