I keep reading that there's some sort of phase/channel bleeding issue in the 2.0 mix on DVD/BD.

Listening to it through headphones, I do hear an echo effect in the music, but I'm not sure that's the same thing they're talking about (there's a similar echo in the 1977 Dolby Stereo mix of Star Wars).

Either way, a preservation of the LD audio would still be good - these same people say the LD didn't have the problems the DVD/BD 2.0 mix has.

I think the widescreen LDs for all the films should be preserved at some point. II and especially III had different color timing (daytime skies were originally "bleached" in the lab to hide the wires holding Superman, Zod, etc.), and the Japanese LD of IV is the 93-minute overseas cut.