I don't think its UA that wants to end Silver as a UAX carrier. UA wants to have viable operational presence in Floria via Silver, but apparently Silver wants something more than just a UAX carrier that is fed by UA. They want some level of independent operation, but they still want to have UA feed them with customers. By leaving the UAX contract to become just a codeshare partner of UA, Silver can sell their own tickets to more customers, and possibly codeshare with other carrier(DL, AA).