My guess is that, as anticipated, they are going to the same "Jack Lite" format that they've alreadly flipped a few stations to. With that signal, it's not going to be a major threat to 'BMX, 'ROR or Magic, but the format will do well enough in an advertiser-friendly demo to survive.
But at some point, CC will have to mount an advertising campaign, as many listeners in the market were scarcely aware that WFNX existed, and the ones who liked WFNX are highly unlikely to stay tuned for 30 seconds after "Bennie and the Jets" or "Come On Eileen" or "California Gurls" starts playing. In a publicity vacuum, it will be lucky to show up in the next Arbs.