I have also reported the sign up error here Not able to sign up for Tour de Zwift - “Your profile is not eligible for registration…”
It seems like they are promoting the tour as a ride for everyone of all abilities. Much of the information is targeted towards users new to Zwift racing and mass start rides.
It would have been nice if there was an alternative in this tour for the more experienced Zwift racers. ZRL is probably their answer to this request. That is right, but there should be interest in a racing alternative to ZRL more geared towards the individual rider.