I, too, think it should be "wait for". The substitution of "wait on" for "wait for" is extremely widespread, at least in the U.S. It is so widespread that may be on the verge of being accepted as correct. (Shudder!)
I have noticed that British people in offices say «wait on». They may say «I am waiting on your report». They mean «I will act when I receive your report». It is strange, I think.