I've been hearing the whole 'Always Online Worlds Will Become Living, Breathing Things, Full Of Immersion And Stuff!' line quite a bit nowadays, and all I can say about that is I used to be a World of Warcraft player, a number of years ago... and while I found enjoyment and immersion whenever I was off on some quest on my own, traversing a dark forest or hellish landscape, the time my sense of immersion dropped to its lowest was when outside people were tossed in. This wasn't quite so bad on the RP servers (which I generally stuck to specifically BECAUSE it was slightly less immersion-breaking) but any time I'd enter a more densely populated area, there would just be no helping the fact that an online community of strangers shatters immersion with a hammer. Even turning the chat off to silence the calls of 'LF Level 35 Mage For Group!' or 'lololol hi!' and other rubbish, I'd still see Night Elves hopping obsessively to create the much-sought somersault leap, people trying to reach normally inaccessible nooks by climbing atop scenery with MORE hopping, folks running around in their boxers just for the hell of it. Goldshire, oh GOD, Goldshire was a nightmare, because it was one of the easiest spots for Level 1 characters to reach, so people who were bored waiting for their own server to finish maintenance, or just bored period, would make a new character JUST to troll there.
Now, some settings, immersion isn't so important because it takes a back seat to competition. I will no doubt play Warframe, Planetside 2, etc, etc, but the point of them isn't exploring and discovering a new setting... it's fragging and laying waste to the opposition. The Division, on the other hand, looks like it involves some exploration and discovery elements, which is why the online requirement worries me. Immersion can be maintained if the game environment is one that has people you know, and trust. I play Minecraft with a few friends, and though we don't do anything extreme as 'roleplay,' when playing we just talk about swapping resources, a certain pet project, etc, etc. But if Minecraft suddenly started throwing random groups of strangers into my game... well, I'd probably stop playing pretty quick, cause some folks just want to watch the pixelated world burn.