i got a rather fast reply from DarkShock over @ Zelditx Forums to Why its missing and with good reason,
Yes because when you leave battle with MSU-1 music it would restart the dungeon from the beginning. And you go in battle a lot during a dungeon !
Once MSU-1 Resume is available everywhere, it won't be an issue anymore 
yea restarting the place everytime you finished a fight in a dunegon would be really bad

i thought i'd just get it out to why it's missing as so many i'm seeing around w/ gameplay vids of the hack articles on certain websites and even over twitter are wondering Why the battle's SPC is playing despite everything's being converted properly.