I think it's a documentation error like Toyota said.
Look at the center console. The Climate Control system is a separate module now. With the Prius it was intergrated into the NAV display. There is no "Climate" button on the NAV head like there was on the Prius.
On the Lexus RX50 there is a separate button, there are climate displays in the NAV system, the voice commands just don't work. If I were a Lexus owner I would be more upset since it seems the commands would work but just aren't activated.
In the TCH I don't think there is any communication between the Climate Control system and the NAV head so Voice Commands will never happen with this design unless some subsequent engineering change is implemented. Just my opinion on that.
J