The latest version of discord, 2.0.0, is not backward compatible. This is because it added phase to the chronaural and pulse voices, and flipped the order of beat and amplitude in chronaural and pulse voices. There are substitute scripts for vim in the README and beginner.discord files to convert from the old style to the new style.
Volumes for all voices except binaural will be twice as loud as they were formerly because of a change in the way amplitude is used.
The big news is the new phase voice. Phase shifting a channel at a beat rate to a fixed phase shift appears to be very effective as an entrainment mechanism. I've only played with it a little but it is pretty awesome.
The phase field in chronaural and binaural voices allows the left and right channels to be out of phase with each other. Again, I haven't played with this a lot. It has some possibilities but I don't think it approaches the phase voice.
Binaural is unchanged so if you were only using binaural scripts, this release will not affect you .
The rest of the changes are basically housekeeping and should be invisible to the user.