Private, Neuro, BDunbar and Don, When you resort to childish sarcasm, you've already lost.
You may be correct, Canon may not choose to make a 200-600 f5.6 zoom, slap a red ring on it and sell it for $3,000. But, that certainly does not mean they are incapable of doing that.
I'm on record expressing significant skepticism as to whether this lens will ever materialize. Craig has put it near the top of his list of expected products for 2016. So, it's fair to discuss where we think this product might fall if they do proceed.
If they do make such a lens, I stand by my predictions:
1) It will be more expensive than the Sigma 150-600 Sports zoom, which retails for about $2,000. How much more expensive, I don't know. I don't believe it is inconceivable that such a lens could be made and sold for $3,000, if Canon chooses to do so.
2) Canon knows that they can paint a red ring on anything and it will have a greater perceived value among consumers, justified or not. Therefore, to justify a premium over the competition, they need to put that red ring on it. (bearing in mind that the "luxury" designation is simply a marketing tool and signifies nothing.)
3) I do not believe Canon will make a lens that does not autofocus with the majority of its DSLRs. I also believe they will not resort to "fooling" their own autofocus systems into thinking an f6.3 is an f5.6. By the process of elimination, that means an f5.6. I seriously doubt that the size of the front element is a major worry for Canon engineers. It's just glass, not gold or diamonds. I admit I could be wrong about this and Canon could indeed make it an f6.3, I would just be surprised by that and I'm open to any rational argument that it could indeed be an f6.3 lens.
It is certainly possible that this could be one more $6,000-$12,000 piece of glass. If that's the case, it becomes irrelevant to me and, frankly to the vast majority of birders and hobbyists.
However, I think an argument can certainly be made that Canon may want to compete against the third parties that are offering 150-600 mm zooms, especially since the quality of those lenses has been quite impressive. One of the other commenters that you made fun of, did make a very valid point, which might need to be better articulated. If you are mainly or exclusively interested in photographing birds, it's entirely reasonable that you might let your lens choices determine what camera body you want to buy -- after all the camera can be a smaller investment and easier to change if you are only going to pair it with one lens.
That's a point that had not occurred to me and would certainly be a reason why Canon may choose to compete in the 500-600mm zoom range. An avid birder could well look at Nikon's 500mm zoom and conclude that they could buy a camera and the lens for less than the price of the new 100-400mm zoom. The old 100-400 zoom has been the standard for birders for years. It's not uncommon for me to see four or five other birders with the lens at the same location. In these challenging times, I doubt if Canon wants to lose that customer base to Nikon.
Ultimately, the only way we will know who has guessed correctly is to just wait and see. Honestly, I'm comfortable with that because I'm not the one on this forum who is making sarcastic comments instead of discussing things in a mature and intelligent fashion.