That's a moot point, really. F95zone isn't required to use the exact same definitions of the term visual novel as VNDB - and there are valid reasons for that.
Both sites just have very different priorities. VNDB is an online catalogue that focuses entirely on visual novels, while F95zone aims itself at porn games of any stripe. So, it actually makes sense for VNDB to use a much broader definition ("if it has visual novel elements, it's a visual novel"), but also for F95zone to stick with reserving the VN prefix only for pure visual novels ("if it has gameplay elements, it's a game").
Hence why none of the threads like
Sengoku Rance,
Collapse of Zeth,
Utawarerumono, or even
Wings of Seduction or
Haremon carry the VN prefix.