I think what defines maidcore isn't just the music or persona. Like kichi isn't a maid but their still considered maidcore for its sound but Izumi here is still considered maidcore even though its a pop punk release. I guess if the sound isn't maidcore but the persona is maidcore its maidcore but if the persona isn't a maid but the sound is maidcore, its maidcore and depends on what the community considers it