Magazine target demographics are somewhat inconclusive, because there are also those examples where you have the same manga being published in different ones (e.g. Dorohedoro was published in Shounen and Seinen magazines)
My guess would be that it was due to the original manga (Peach Girl) being a Shoujo manga, so it'd make sense for further entries to share that demographic
But if you feel it's still not quite accurate, you can make a submission and include that change and your reasoning in the notes section of it
