According to the one person who has ever talked about the game on Saikey's discord, the December looping thing was a bug that got resolved in a new patch like a month after release, and they made no mention of the voices being removed. So either Ryuugames decided to mess with the patch, which I don't know why they would, or Saikey ran this thing through an AI that stripped the VO prompts and dumped it without doing any QA on it. Which wouldn't surprise me, because I remember seeing something that most of Saikey's work is AI.
Basically, there is no fix that we can do for anything.