The mix could have been tweaked after one mix went out the door, but before another was shipped to theaters.
If I’m not mistaken, there are four audio formats for TFA. Dolby Digital, Atmos, Datasat, (formerly DTS) and whatever the sound format used for 70mm Imax. The signage at the museum where I saw TFA mentioned the soundtrack is on a DVD that plays in synch with the print.