If he’s withdrawing from ALL DOJ cases that means something...
Is he going to try to claim the DOJ misled him?
If he’s withdrawing from all DOJ cases then it almost certainly means he’s aware of something that will impair his ability to function as a licensed attorney in Federal courts.
Probably trying to avoid contempt or judicial discipline.
Much more complicated to impose if no longer a lawyer before a court.
I think he is being forced to. Otherwise when this gets overturned all cases he is working on are suspect.
A quick google seems to confirm this is the only case he is reported to be withdrawing from.