"Remix" was already a well-worn DJ term by the mid-'90s but the internet's favorite generational solipsist Brad Troemel seems to think people started using it 5-6 years ago. The historical gaffes in his writing (such as pegging surf clubs as elitist when the biggest gripe about them at the time was they had no standards) make you wonder about his editors. The chart above (from his latest screed) seems to rather state the obvious and if you're going to call an essay "The Word 'Remix' Is Corny," you might give some thought to how "progressive versioning" rolls off the tongue.
Troemel cites Rauschenberg's Erased De Kooning Drawing as an example of an "A-to-B Remix." Retroactive continuity aside, that's really an excellent example because Aphex Twin and Omni Trio were so well known for turning other people's recordings into virtual silence.