I'd be willing to bet that Nikon is not in financial trouble.
And, I'd also be willing to bet that the reason we aren't seeing a D400 is that Nikon has done a market study that shows there is more of a market for a less expensive DX camera for advanced amatures (D7200?), and that it is more profitable to make pro-sumers "move up" to FX to get the pro layout and AF system. And, to hell with those of us who can't afford long, fast lenses for shooting sports and wildlife on FX. We're a niche market, I guess.