: : The long walkway room won't display properly in map view just like the
: I think they got that to work from the very start
Yep, the map handling was unchanged since Marathon. I believe the rule is, a poly displays on the map if at least one vertex is within the map bounds. Here and other places, Marathon has some really huge polys where you can stand in the middle and have all the vertex points out of bounds. The only change in M2 is that they stopped building levels that broke the map.
Of course, M2 did break checkpoints in the terminals, but that's a different story.