I think the fact that Jazz wasn't going to operate the Island service was probably going to cause some confusion for people who would be expecting AC service and not Jazz service when they showed up for the flight.
Basically, I think they were just going to create confusion by having all these little airlines providing regional services, but people know Jazz as the regional carrier and don't think there are others. Of course, since Jazz is now Chorus, they could have just rebranded the entire regional network as Jazz instead of Express and been probably 80% complete already LOL.