I thought those ghostly vocal reverberations were perfect for this arrangement - they added a (very) unique atmosphere to the song, without going too far into embellishing it like the strings in the single version did.
I liked the strings at the time, but in retrospect they make the song sound almost... Melodramatic? Like something made for a TV drama. This new version sounds far more eerie, and intimate, which is what the song really needs. It's also pretty bold, it gives me echoes of Radiohead and sigur Ros.
However I think it's so 'unconventional' that I can understand them not being bold enough to put it out as a studio release, even if I think it would've been great.