I'd put my money on the fact that there will be another European run of shows either at the end of this year or perhaps the beginning of next year. However, I'd also expect that there will be an Asian/Oceania leg of the tour, and I could easily imagine them planning on shooting the video at the Sydney Opera House, since they've never done an official video in that part of the world and that venue would be perfect for such an occasion (or at least I'd imagine so, never having been there and not knowing much about it).
If they are going to be touring the US in October / November, I cannot believe they will do another run of shows playing just The Astonishing, so soon after the first leg. Will they do an “Evening With” type show, containing excerpts from The Astonishing, plus other songs ? Will they play a one off show during this run, as a massive 4 hour + event, where they play The Astonishing in its entirety and then follow it with other material, similar to the Live Scenes from NY show in 2000 ?
Or will they play some more shows in 2017 just featuring The Astonishing, one of which will be filmed ? If the latter, where will this be ? Surely not during a third US leg ?
I recall reading/hearing JP make some sort of comments that if they were to do a live video, that they'd probably include an orchestra and choir for the occasion. But obviously, it would be a one-off type of situation, given the massive expense of taking that many people on tour with you (or even just hiring local orchestra/choirs in each city, like what Page/Plant did in 1995).
As for the upcoming NA leg, yeah, they just went thru NA recently, but there's a lot of places that they didn't visit on that round of shows, so I can easily expect that the vast majority of the dates will be in cities not covered on the first NA leg of the tour. In fact, I wouldn't be surprised if they finally do a string of dates in Texas and the deep south, which has never gotten any Evening With shows from DT - after all, Indianapolis finally has a tour date, and DT hasn't played there since 1993!
Likewise, when they go thru Europe the second time (which I think is all but a given), they'll be visiting a lot of the cities/countries that were missed on the first European tour. So I wouldn't expect many of the same cities to get dates again, aside from some of the big ones (London, Paris, etc.)