I think this is a false statement as you can clearly see that the Nü Metal favoring died around the time that Linkin Park decided to "change".
To say a band does not sell out is a very undermining statement, as creating and selling music is their career. Obviously, you will not hear a band getting mainstream airplay with a banjo, no pitch correction and recording straight to tape. There are sacrifices bands make to sell more records, such as making something that is new or with the times.
This particular album has sparked my interest so far because it reminds me of those roots they once had on Hybrid Theory and Meteora. You will also find that they mentioned this record was not made to sell.
Now take into the equation that a good portion of old school fans (myself included) are favoring this record and disliked Minutes to Midnight.
I can't pinpoint it, but I wind up really hating the mainstream music on the radio. Minutes to Midnight fit in with all the other mainstream music quite well, it had that mainstream "structure". They gained a much larger fan base with Minutes to Midnight due to the fact that the record was not Nü Metal, Rap-Rock, Rap-Metal or whatever you decide to call it that seemingly died off however many years ago. It was in fact, a modern day easy listening record that a good portion of the world could pick up at a local music store and jam to.
With A Thousand Suns, they are taking the time to express they made this record from the soul and not to sell. This could implicate that they are in fact returning to their roots that made them famous to begin with because their trademark sound was an entity of its own. Their "roots" are who they originally were as a band. They were experimental yet easily recognizable because they were one of a kind, just like you hear on Wretches and Kings. You don't hear that so much on Shadow of the Day...