Why now? I think it will put more pressure on the Reps and Trump to put their act together.
They will have to appeal right away or put out instructions for DACA renewals.

1. If they appeal right away, and the applette court or supreme court stays the order, the optic makes it even greater urgency to pass permanent daca fix.
2. If admin don’t appeal, however unlikely, it basically admit that the termination of daca was done improperly, and will have to put out instructions asap for renewal and do it properly with APA on ending DACA.

Essentially this order dares the administion not to appeal.