...so, I stumbled across this, accidentally, when reorganizing my lossless library. Track 11, "The Troubles" from SOI, on both CD and iTunes has a frequency cutoff above 16Khz from about 3:30 and afterward.
The same is not true, however, of the audio portion of the music video found on the i+e Paris DVD and Blu-ray releases.
CD: Attachment 1
iTunes: Attachment 2
(Music Video from) i+e DVD: Attachment 3
(Music Video from) i+e Blu-ray: Attachment 4
I can only assume this is an unintended file data corruption that was pressed to all cd / digital masters. Having tried a couple of different cds, as well as various online digital releases (both lossless and lossy), they all have this "glitch," while the music video audio appears uncorrupt and pristine.