A couple months ago, I booked flights from Shreveport to JNB via ATL on Delta. I got the Premium Select with miles for my daughter and me. The connection time in ATL was a little over 3 hours, which is perfect. Recently, Delta changed the times on the SHV-ATL flight and the connection time in ATL became a little over 1 hour. That's too close for comfort, so changed to an earlier flight which now gives us a 6+ hour layover in ATL. Sort of longer that desirable, but it is what it is.
Delta has also changed rules on the Business Lounge usage. I read somewhere that Delta will now limit lounge use to only 3 hours prior to your flight.