I don’t think I like this. Facebook and Twitter are universal networks with wide appeal and immense scale; it almost felt obvious that they should be tied deeply into iOS’ core. LinkedIn, on the other hand, targets a niche market that — frankly — not many people like.
Whereas adding Facebook and Twitter felt like a natural progression, putting LinkedIn options into the Settings app treads dangerously close to seeming like bloatware-esque clutter. It evokes the idea that Apple is more interested in closing business deals than making partnership choices which are best for the user experience.