yeah, it has been done before. Over in Japan, the Godzilla & other Toho fx films on DVD (& now bluray) were released with the original mono, stereo, or "perspecta" surround audio tracks along with new 5.1 surround remixes. Some of them just had one original audio plus the new 5.1 track, but many had multiple options because the original theatrical releases had both mono & either stereo or perspecta releases, much like Star Wars.
To take it one step further, during the mid to late 70's, the original film-makers recut their own Godzilla movies from the 60's to make shortened versions for the "Champion Matsuri" children's film festivals. These re-edits were also released on laserdisc, dvd, and now are being included on the blurays when available. So even halfway across the world people are given the choice of which film edit & audio track to watch on home video.... C'mon, George!