This has a very similar premise to A Monster Wants to Eat Me, so doesn't it feel a bit played out to debate if this is yuri or not? Both of these series employ a story mechanic that we could call "cannibalism edging". Even without the cannibalism, a relationship where a girl hangs around another girl who intends to kill her has a pretty clear eroticism to it.
Yeah there's no question about the queerness/yuri in this story (even setting aside the fact that it's tagged as yuri on bookwalker). I can only imagine that some people are perhaps new to the genre and don't have experience reading anything outside of the "school girls looking at the camera and telling us they're lesbians before kissing" genre.
Horror has always been a very queer genre, I mean famous works like dracula and carmilla both come to mind as being some of the original works that we could categorize as "modern" queer literature. The intimacy of stuff like cannibalism or taking on someone else's body and identity is all very well established in the realm of queer and sapphic horror.