Might not help in ATL due to how it is set up. But if you arrive in ORD at T5 and need to connect to a flight in T1/2/3, it would help. Would also help in quite a few other airports. I think of JFK and LAX in particular where all terminals are not connected airside.
In theory, it could help in ATL. TSA could put a Pre-Check lane at the re-screening facility in Concourse E, where arriving int'l pax recheck their bags and pass over to airside again. It could also help at the main outbound checkpoint in the MHJIT, Concourse F.
I'm departing on Korean Air a week from today. If no one else reports between now and then, I'll post about the experience departing from the international terminal.