Too many variables to determine.
I religiously do pan drops on all my vehicles at 30K.
That interval was good enough to take the original transmission on a 2000 Taurus out to 275K, yet a transmission on a 1993 Chrysler died at 66K on that same interval.
The Taurus still shifted perfectly on the original transmission when I got rid of it at 275K. The Chrysler was rebuilt (under warranty) and was never correct. I traded it shortly thereafter.
That doesn't exactly answer the Toyota question, I know. However, it does make the point. Design, quality of components, and intervals of maintenance are all factors in the longevity of a transmission.