In either case erosion would erode the surrounding land and leave the old channel as a raised ridge because the ridge will be more resistant to erosion. An image below, taken with HiRISE of Antoniadi Crater shows sinuous ridges that are old channels that have become inverted.
In either case, erosion leads to the degradation of surrounding terrain and leaves behind an elevated strip of land that was formerly a channel, as the ridge proves more resistant to erosion. The image from HiRISE shows sinuous ridges that are old channels turned on their side.