I just don't see WSVN and Fox parting ways, especially now that the Dolphins get many more games on 7 with cross-flexing and the snowbird crowd happy with their college sports coverage, along with the rare Marlins game (and don't forget the World Baseball Classic, whose de facto championship home site is Marlins Park). There's no benefit for Fox to go to the Scripps pair on 35 or 39 at all, WSVN provides them enough resources in the market, and you know very well that promotions department is beyond psyched to put a new spin on a "Power of Two" marketing campaign, especially in football season. And simply I don't see WSVN interested in individual team rights for the other sports like WSFL is.
And I disagree about Fox's lack of scripted programming, they're just more judicious and selective now about what shows they roll out (Doc and The Cleaning Lady are both pretty good and perfectly tuned for a Miami Fox station). They know they don't need to compete with Netflix and that's how their primetime feels like; we're still far from a subpar lineup comparable to UPN or MyNetworkTV.