Interestingly enough, pushing the AMB button on my MazdaSpeed6 displays the outside temperature and it stays in that mode until I either (a) change the temperature or (b) push the AMB button again.
On the CX-9, we have dual-zone climate control allowing the driver and the passenger to enjoy different temperature settings. So, whenever you turn the climate control on, it indicate both temperature settings. I don't know if it is possible to change this behavior.
In my previous car, Nissan Maxima, There were 3 seperate indicators, driver temp, passenger temp and outside temp. Maybe, the next gen CX-9's will have that. Maybe they can incorporate the entire climate control into the Nav screen!