the sniper bit is pretty cool, there's a bit of an unsettling backstory leading up to how you get the rifle
you can find another sniper rifle later in the game and use it during another mission, but it's not a straight sniper sequence
i don't think it was contract fulfillment, i think they got in over their heads with UE3, and know the game is flawed, but had to get it out - which is why they went from talking up multiplayer a couple of years ago to just passing it off to rockstar
spoiler (click to show/hide)
there's going to be a fourth (probably final) BiA game - Battle of the Bulge, etc. i bet that's where you'll see the multiplayer they were talking about years ago