I don't think FOX protects games now for week 16 by the way. It all happens much closer to the actual date. I think when week 14 is in the books, they can protect games for week 16... and as you noted, the logical game for FOX to protect is Saints at Cowboys.
I agree 100% that if our game has the potential to be a knock out game for us i.e. we have to win or we aren't in the playoffs OR if it has the potential to switch the NFC West around i.e. with a victory we'd move ahead of the 49ers in the division -- either of those hold, we're pretty likely to have the game flexed.
There are some major stinker games in week 16, hadn't noticed that, and yes, there's no way the Chargers Jets game holds up, that's for sure.
(I suppose FOX might protect Giants at Baltimore, just because those media markets are so freakin' huge, but if the Cowboys and Saints are butting heads over a playoff spot, that'll be way more meaningful.)