The mechanic is wrong (didn't want to bother with it that day ?) and the second dealer is only partially right. The owner manual (maintenance guide) say to change it at 60K but for severe usage. Otherwise, inspect every 30K.
As I understand it, the conventional, 4-speed automatic requires a fluid change at 60,000. The CVT is considered to be a "sealed unit" and the fluid is intended to last the lifetime of the vehicle.
Dealerships will "recommend" a great deal of frivolous services for your car....it's a money game for them. Many dealerships will sell a car at cost to get month end numbers up to get manufacturer's incentives. Dealerships know the money is in the Service Department.
I've followed the Toyota service manual for years and have had several, high-mileage and no trouble vehicles. Be wary of the dealership's"recommend" services.