After finally seeing the French trailer I am not convinced that the sabers have been altered. It looks like any anomalies may simply be the result of color and balance and re-mastering. And the Death Star explosion appears to be the same as the Special Edition. However, the cell bay definitely looks altered. I made some comparison shots you can check out here. On the screenshots I took of the originals I adjusted the brightness and cropped the sides to more closely match the French trailer.

Also, for those who haven't yet been able to see the French trailer, I edited the relevent parts out so everyone could see them for themselves. Download here. (1.7MB)