Even if there was a 2nd version of the 100-400, which there isn't, you wouldn't see it, because the lens is variable aperture and slow.
-The same reason you never see a 400 5.6 there (which is what the 100-400 turns into at 400)
-The same reason you don't see that many 200-400 f4s there
-The same reason you see tons of 300 f2.8 and 400 f2.8s there
Not to mention, there's still no way to tell through the television because they never show full screen shots of the photographers. On top of that, most updates look pretty much identical to their predecessors, so unless the lens takes on a whole different new look, you still won't notice.
How are all of you so gullible?