User blog comment:ChishioKunrin/Volume 7 Bingo/@comment-35455126-20190710200849/@comment-4010415-20190711175343

@Glitchee I talked about Ciel and Theodore because I was pointing out other characters whose names appeared in the files before they were introduced, just like Yue.

In other words: I was saying that Yue most likely will appear at some point because her name was in the folders that we saw on Monty's computer, just like Ciel and Theodore's. I especially brought up Theodore because the photo of Monty's character folders is from all the way back in 2014 and we are only just now learning that the Shade headmaster's name is Theodore in 2019, in a novel. He still hasn't even appeared in the show yet.

If it takes 5 years for Theodore's name to finally come up in some form of canon material and even longer to come up in the show proper, then who's to say it can't take 5 years for Yue to show up as well?