Thanks for the input, Malm. I suspect, though, that it has to do with the nature of the buildings themselves. They don't have doors on all sides. You can have two buildings squashed against each other and you can't move interally from one building to the next. This is realistic, yes, but in the interest of moving my troops the most sensible way, I want to know in advance just where the doorways actually are so I can plan a safe route, or abort the attempt at all.
I tried one approach, which was to set their movement to Sneak, which would have them move really slow and then the AI would tell me the next turn where they planned on moving. However, Sneak was just fast enough that they snuck right out into the open, drawing fire from two or three squads.
Maybe another trick would be to set Pause to the maximum value, and then set Sneak or Crawl, and see if the troops will get started just enough that the next orders phase I can see what the AI has in store for my troopers.