Cadillac never made center console for the second row as far as I am aware of. I know that there are cup holders located right below the rear passenger ac and media controls. If you ordered bench seats, then the cup holders are located back rest of the middle seat of the second row.
You could just leave a feedback for Cadillac to give people an option to have a center console in the second row.
We had a console between the second row buckets in our 2009 Yukon XL - they plug into a tray that is mounted to the floor. I'm sure you could find one salvage with some effort. It was sort of pointless for me though, as we regularly use the third row. One plus was that it held a LOT of stuff.