There is no real point at all in Apple upgrading the current 16" Intel further. Its not worth it, and as being said the 5600m model is in fact a superb laptop if you need windows also [It spanked a 10th Gen HP Zbook workstation in nearly all ways except GPU performance when I compared].
The next M 14/16" MBP are certainly going to be awesome computers, and I will be getting one. But if you need a laptop right now I wouldn't be concerned about buying the current 16" [5600m only]. The only negative is it gets quite warm on the lap, but is great to use on a desk. I agree with all the points
@rawweb made earlier.