They have a very long tongue that wraps around their brain. This article is stating that’s just to store the tongue and isn’t some sort of bumper for the brain.
Slightly incorrect - the researchers only looked at bone structure. This was an evaluation of a theory that woodpeckers had an energy dissipating section of bone that protected their brain. That would make for a safer brain, but a worse pecker.
The tongue may still have an effect, but a different study methodology would be needed in order to test that theory.
Now I'm wondering how that's gonna work. De-tongue some woodpeckers and see if they get concussed? There's not any imaging that would work for this is there, where we could paint or inject their tongue with some dye and watch it flex inside their skull? that'd be a lovely video if it could be made.
The tongue may still have an effect, but a different study methodology would be needed in order to test that theory.