RTC's reply to my question:
"The project is defined as Rainbow to Nellis since that's where the roadway improvements will take place as far as a dedicated bus lane. However, the route would extend to the ends as they do now on the existing Route 202. Unfortunately the information provided on the website understandably leads people to believe an express route would only operate between Rainbow and Nellis. If this is ever constructed, we have full intent of operating the route from the current Grand Canyon area to the Cannery and make use of the dedicated lanes between Rainbow and Nellis.
Thank you for your feedback."
Okay, I'll take back what I said previously.