Yeah, from what we've heard and seen, there's a bit or that. It's probably partly needed because of technology (harder to have one huge seamless level), and party because of the way they designed the objective completion system... -- there are individual steps toward the goal and they get marked as completed or cancelled as you go along, for example. Even though there are multiple paths you can take, they seem to kind've want you to have an overall linear progression through each level.
Certain pathways you choose even become points-of-no-return; like if you use a rope arrow to enter a window up high, you might drop down 10-15 feet through that window and not be able to get back to try one of the other paths you could've taken before the rope arrow. (That's how it seemed in one of the videos anyways.)