>What is much more likely reality is that they detect breaches on a regular basis, and until the forensic team came back with the bombshell - likely many weeks

>What is much more likely reality is that they detect breaches on a regular basis, and until the forensic team came back with the bombshell - likely many weeks later - of the scope of the data loss, the executives were not even informed. Your hypothesis is predicated on the fact that you trust their timeline, and make assumption that type of events could have occurred within each groups at Equifax on those days..