I'm not seeing what you're all talking about with missing/sunken mountain ranges. I even did a quick overlay to confirm:
Dark Green = Current Land Masses (and future flooded/sunken areas)
Light Blue/Gray = Projected Land Masses
Yellow/Orange = Irradiated Areas
Light Green/Blue = Current Water Area
The images didn't map exactly but I think it's close enough to see that the mountain ranges being discussed are unchanged. Yes?
The only major issue I have is with Greenland. I'd read once (don't recall the where or when, some geophysical text or other) if the ice covering it were removed (melted) that besides raising sea level globally (some small amount) it would also raise the entire continent by much more as the weight bearing down on it is removed and the crust rebounds (no doubt with some extreme vulcanism thrown in). So I can't really see it disappearing, and I wonder if the poster of the map mistakenly imagined Greenland was all (mostly) ice?
Quick google for what Greenland would look like without ice:
Other than that the only other remarkable is what happened to Eastern Canada. Quebec obviously finally got the Separation they were looking for and took the Maritimes with them. Loaded the whole lot onto a heavy grav lifter, covered with a dome, and lit out for the stars I guess
