It's not difficult to nail down when a slab leak is or isn’t a true emergency. What feels like an emergency to someone may not feel like an emergency to another. People will differ about what the threshold for an emergency is. There should be a presumption of good faith involved in any healthy thought process between what is and isn’t an emergency.
Here is my opinion that you can choose to use for establishing when a slab leak is an emergency:
Would delaying finding the slab and doing the repairs likely result in damage to the property or cause injury to you or a member of your family or neighbor?
Is there water coming inside the house somewhere and there is a definite need to have to shut the water off?
If the property doesn’t have water coming inside the house then it's still livable. You could turn the water on and off only on an as needed basis. Keep in mind The Water Leak Detectors is here to professionally find your slab leak in your time of need.