As long as we talk rumors, I would replace the 70-200 f2.8 by the rumors 70-200 f4.
As long as we are talking rumours:
1. The 3x zoom range limitation seems mostly to apply to bright constant f/2.8 designs; there are optically good f/4, f/2.8-4 and f/2.8-3.5 zoom lenses around with 4x and even 5x zoom range.
2. There is little modern need for a constant but not very fast minimum f-stop, now that the f-stop can be held constant through zooming on a variable minimum f-stop zoom lens so long as the desired aperture/focal length combination exists. So I see no advantage for constant f/4 over something like f/2.8-4. Not even in size, weight or cost, since that is dominated by the maximum aperture diameter needed at the long end.
So I offer an upgraded rumour of a 70-300 or 75-300, f/2.8-4.
At least, that is what I think Nikon (and Canon)
should be offering us, instead of this bizarre drop from f/2.8 at the long end to f/5.6 at the long end as soon as the long end is beyond 200mm. (With the exception of one fantastically expensive 200-400/4)