Anyone know what's going on in Chicago Union Station South Concourse?

Howdy all,

I took Amtrak from Milwaukee to Pittsburgh and back over the past week, stopping in Chicago during my layover each way. The North Concourse still allowed seating by the departure gates, but the South Concourse was blocked off for seating unlike last year. Employees had us wait in the Great Hall and then get escorted down when it was time to depart. Now, I much prefer waiting in the Great Hall than by the gates, but I'm curious, is there some sort of renovation going on? All the employees I asked about it didn't know the reason behind the closure.