Name me one OT that is not Dark Souls or BF3 that has new people coming to it all the time after the first few weeks. The truth is they almost exclusively get a subcommunity of five to fifteen people who don't give a crap about what the OT says because they're talking to each other in the thread.
OTs shouldn't be a compendium of all the information that exists on the game because there are other sites whose only point is exactly to host that information. OTs should contain the bare essentials of what one needs to know on a game, like when it releases, a picture or two, what consoles it is on and a few distinguishing features, and then be updated for updates on the game. If you can keep this information, with updates, within a single post, then you probably have all the important information that currently exists for the game packed efficiently.
No one who's thinking "I missed this whole Assassin's Creed thing, I wonder what it is" will go read up on the AC: R thread to get that information. They'll google it or something. The people who'll read the OT are people who already know all the ridicously superfluous information in it. It's not worth the time people are taking.