That almost definitely is due to the extended versions of those movies being finished on video rather than film. That's probably why the song has been missing from this movie in various incarnations too. If I had to bet, I'd say that they won't go back to the film elements of the deleted scene/song and re-edit it back into the film so I think it's going to be MIA here too. As for it still being 1.33, I think that's all but impossible. Given the age of the DVD, they are most likely doing a new transfer for the Blu-ray and if that's the case, it will be 1.78/1.85.
The movie was produced on 35mm film. The song, being part of the movie, was shot on film as well. Director Brian Henson wanted the song included on Homevid and it was - mastered, as it could only have been, from the film it was shot on. The first disc release was a laserdisc that had the complete film
transferred in Original Theatrical Aspect Ratio
. The first DVD was 1.33 and was complete with the song. The last DVD added a widescreen transfer that was missing the song. However the song clearly does exist in its original OAR, - on film. If going back to the complete film elements to produce a new complete DVD in OAR (especially for a BRD) is too much trouble for a film company, they have no business asking us to buy it again. According to Matthew in a previous post here: "Blu-ray.com claims "1 movie, 2 cuts," which is encouraging." And if they plan to again include the complete version, but NOT go back to the film elements, then they WOULD be including the 1.33 version again, just like the last disc - unless they threw in the old laserdisc transfer as an extra like Fox did when they dumped the superior 65mm version of Oklahoma! onto disc 2 as a lowres supp.