I assume there are licencing issues, as they might need to negotiate the all the rights for the songs again.
on the other hand, would it be possible to “cheat the system” and allow users to also get the original game, unremastered and if the original, with the original music is installed, the remastered version could be made to read the music from the original files.
maybe even just call it an extra 1$ dlc for the original unremastered.
anyone ready to reopen the “is avatar anime” debate?