It's not unusual that the "shadow docket" orders have limited briefings when the extent of the ruling/order is usually procedural, as opposed to ruling on the merits of the case.
It should be noted any justice can write a dissent in a "shadow docket" ruling. If a justice finds a ruling incorrect, nothing hides their criticism of it from the light.
This mechanism means that regardless of how awful the Trump admin proposal one SCOTUS justice can "temporarily" unblock it giving no reason at all, and then the "real" merits case can be slow-walked.