Not every unit requires this type of counseling, but many do.
The purpose of the counseling is to document the informing of a soldier that because they are requesting leave that would reduce their leave days balance to below 10 days, any situation that would prescribe emergency leave for a soldier with fewer than 10 days leave following the already taken leave would only be approved if the circumstances were categorized as "locale parentis." Locale parentis refers to an event taking place within the established maximum distance allowed soldiers from their duty station when not on pass or approved leave.
Here's an example of why their leave request warrants a counseling:
Your soldier (we'll call him Joe) is stationed at Ft. Drum, NY, and by SOP, his unit allows him to travel up to 250 miles from post when not on pass or leave. Joe requests leave that would make his remaining balance of leave 3 days. He's approved and takes the charged leave. Shortly after returning, Joe's uncle, Jim-Bob (who lives in Oregon), dies suddenly. Now normally, Joe would be able to take chargeable emergency leave to his uncle's funeral. But now, since Joe only has 3 leave days, he is not approved for emergency leave because the distance Joe would have to travel will be outside the 250-mile maximum allowed travel distance. Now Joe is sad because no one told him that this was the risk he took when he signed up for leave.
Now if Joe's uncle lived within 250 miles of Ft. Drum, NY, Joe could have taken chargeable emergency leave with no issues.
Soldiers need to be made aware of this, as it is a common SOP for many units (not all, of course). And a counseling is the perfect way to document that conversation.