So does this mean that each map will always have exactly the same objectives? So lets say one map requires you to escort someone.... Will you always have to do that on that particular map?
There are 2 missions for each map, and each mission can be taken from both sides.
So you'll have a total of 4 different paths through the mission.
Also, each mission is multiple objectives, not just a single one.
For an escort mission, it's not going to be "get VIP from A to B" and nothing else.
You start off "break into compound" - when that's done, new objective "Release VIP from prison" - from there you finally get the "escort VIP" part.
This is a made-up example, but it gets the point across. The mission changes as you progress.