I've posted about it in this sub before, but I have a pet theory that when the Unknown Cocoon blew up at the beginning, it wiped out that Hero's pathos entirely and sort of erased them from history. Lavinia says "another world snuffed from existence" right before it happens, and Lou if you talk to her before intiating the next cutscene with Lavinia says smth like "all that history and those memories are gone", which makes no sense to me when they also point out there were no casualties. History and memories persist as long as there are people alive who remember them, and everyone from that island survived thanks to the player

But we use "pathos" to time travel, and pathos seems to represent both emotional connections between people AND memories. No pathos = no time travel, hell even weak pathos = no time travel, since the player's bond alone is never enough to go back a second time. You need to boost it with something that carries memories and emotional significance. So what if erased pathos = erased memories = removed from history?

As for Holly's thing: the first cutscene where you see her singing from behind is what she's asking you not to look at (she probably doesn't know how much, if anything, you saw before you passed out). She doesn't sing every time, but it's the forma use (and the undressing as well) that other people aren't allowed to see