...My assumption is that the 7DII will be a (feature wise improved) crop version of the 5DIII, not of the 1DX. Otherwise it will be far too expensive, the 7DII logical price point will be below the 5DIII.
That I agree with.
Of course, it's hard to predict a trend when only one 7D and three 5Ds have been produced, but it does seem that Canon positioned the two as basically paired versions of one another. Since the release dates vary by a couple of years it's not surprising that one model tends to leapfrog the other in certain features, but for the most part, they seem to be comparable. Which actually makes a lot of sense.
Give 5D owners a crop version for the reach and other advantages of that format but retain the same basic operational features so its easy to move from one to the other.
Get 7D users used to the same basic feature set of the 5D so that if they decide to try full-frame they are more likely to go for the more expensive 5DIII over the entry-level 6D (that strategy worked with me, by the way).
I've long said that Canon's goal is not to move people from crop to full frame, but to sell enthusiasts, semi-pros and wedding/event photographers two bodies – one crop and one full frame.
I think there is a outside chance Canon could produce both a 7DII that mirrors the 5D and a "7D X" that is targeted to the professional shooters that still miss the reach of the APS-H format. I don't know how large that market might be and whether it would be worth the investment for Canon to produce such a high-end crop sensor. But, regardless, the primary 7DII is likely to remain paired with the 5D as you say.