If you are using Komplete Kontrol hence the Mackie I just did the upgrade and it automatically applied all the settings. The only difference I notice in the device manager is that Mackie Control is not showing. All midi in and outs are ticked and it works perfectly.
Whoops of course opening an 8.5 project would be fine. Opening new project in 9 need to reconfigure mackie control. Will let you know how it goes later on.