I feel like The Offspring is one of those bands that's popular and well-established enough that the label won't need to interfere in order to sell their stuff. Similarly, I think they're also well-established enough that they don't need to be on Fat Wreck Chords. Or any label for that matter. It's 2013, more and more bands are getting away with self-releases.
I can only assume things about their writing process, but the band has always had this confidence about their music that to me doesn't suggest "this song was better before the higher ups told us to change it".