I wouldn't be surprised if they offered both. It has been spied with the normal shifter.
https://www.supramkv.com/threads/toyota-supra-interior-looking-more-production-in-latest-sighting.607/
lol if the Z4 turns out to be sales flop while the Supra becomes a major hit. I wonder how would that make BMW feel and or react. Like would they pull the plug on any updates or future joint projects.