Hi OP, just wanted to share with you our experience on 9/18. We were also told to go to the Chamber of Commerce building for our 9:30am tour, so we did. And we sat there all alone for almost 15 minutes before a Cast Member came to the desk. We asked about the tour meeting place, and he said "oh it moved to Town Square." They had not fixed their website or confirmation.
In Town Square, we checked in at the desk on the right as you go through the main entrance. You can hang out at the waiting area for Tony's while you wait for your tour to begin.
This all might be different for you as you have the early tour and they may direct you correctly, but for anyone who is just coming in with the masses after the Welcome Show, you may be confused. I'd say check both places just to be sure.
Enjoy the tour! It was so fantastic. We had Kevin from North Carolina. He was very good!