Since you can't seem to swing a cat without knocking over a fairytale retelling that centers a different character from the original lead, you know who I want to hear from? Bluebeard's first wife.
Because, like, you can assume that every wife before the one we follow fell into the same trap of finally opening the Forbidden Closet of Mystery and discovering the hidden corpses, and was then killed to protect the secret...but the first wife would have no corpses to find. So why did he kill her?
Was it just for her money, and that's how he became rich enough to woo all the others? Was she getting ready to leave him for whatever reason? Did she cheat? Did he cheat, and kill her in the confrontation after she found out? Does he have some sordid criminal past even before his string of uxoricide, and when she found it, he killed her to protect that? Did he simply, over time, come to find her odious?
I know this was never a consideration in creating the story, and it doesn't really need to be, but...what goes on?