As I've mentioned earlier, it is advertised as yuri in Japan, so it is "officially" a yuri. With that said, I think I'm about one more comment like this away from removing the GL tag from Mangadex. I would like to maintain parity with how the manga is officially advertised, but you (and others) are correct that the tag probably sets the wrong expectations for a lot of readers.
(After some more thought since last time this was discussed, I wonder if the label was applied by the publisher as a sort of content warning about the lesbian sex scenes?)