Thanks for your feature request.
I am not sure how you are able to combine .ai files on Mac using Acrobat as we do not have this support neither for Windows nor for Mac for .ai files.
However, we have taken your feature request. It is under review.
An error occurred while saving the commentBrekke commented
I too am having this issue - in my case, I am going from a Mac workstation to a Windows workstation and missing features that I used to have in Acrobat for Mac. I used to combine .ai files into a single PDF all the time in Acrobat for Mac and now cannot on Windows. This feature was a huge time saver for me and my workflow - it would be nice if Adobe could maintain consistency throughout platforms for the same experience no matter what the workstation.