What do Florence and the Machine and The Weeknd have in common? Both make dark music, although Florence's music is dark like Child ballads and Abel Tesfaye's music sounds more like what those ballads' creepy murderers would hear inside their heads. Both have the endorsement of Drake. By the transitive property, then, of course The Weeknd would remix a Florence and the Machine track. It's Internet serendipity!
Unsurprisingly, the Weeknd's treatment of "Shake It Out" is very much in character. The Tedder drums get the kibosh in favor of more skittish beats, and the "shake it out, shake it out!" chorus becomes pitch-shifted and ominous, not celebratory as in the original. For most of the track, though, Florence still sounds like Florence, which is always praise.