There is literally a thread that outlines the stuff that will be in the game as well as the online requirement. And that thread only had 4 pages....I don't know what that says about the people who are interested in the game if that thread isn't exploding like this one.
http://m.neogaf.com/showthread.php?t=1433174
The link, the details and specifics that says, majority of the functionaility of the game will be online focused and verified was pretty much listed there. And again, I don't even care for GT, but I don't think anything here wasn't clear. The point from the get go was that it is online and will have very miniscule offline abilities. I don't know what to say if anyone who is actually interested in the game missed that thread or just assumed everything would stay the same.
The thread is fine for what it is, because it's telling you why it's limited, but it's not "new" information. Also interestingly enough, in the same article that was kind of omitted from the OP, the author of said article even mentioned that Sony did warn of this situation. So again, I don't know what the big deal is. If they didn't mention it period and if the box itself didn't have such information listed, then I could understand...but I don't think anything here was not stated.