Manage automatic creation of direct reports group

Surprised to see this appear in my (and my customers') Message Center. At first blush this does seem like a very poor idea.

What if the manager already has a DL for their reports that they're happy with? They get a Group created anyway?

What if the manager already has a Group, or a Team that is being actively used? They get Yet Another Group created anyway?

Will the Group membership be auto-adjusted over time? Nothing indicates that it will.

If an auto-created Group is deleted, does it get recreated automatically later?

This seems like a semi-useful feature if it was opt-in, so you could carefully set up your reports/manager relationships, turn it on, and have them automatically created and managed. But as an opt-out feature, I am concerned this will mess up the GAL of many organizations, and mess it up quite badly.