If something changed suddenly — standing water under the house this week, a floor that went from firm to soft, a sealed crawl space reading high humidity — call rather than wait for the reply. Those move up the schedule.
While you wait
Two things that make the inspection sharper. Put an inexpensive hygrometer in the crawl space if you have one and note what it reads. And walk the perimeter during or right after the next storm to see where water actually goes. Those two observations answer most of what we would ask on the phone.