I was kind of looking forward for Z to be released in west, too bad that never happened :\

and if you look at warriors franchise, its a common thing (Xtreme Legends, Empires....).

They're not expansions, they're actual different games, not like WO3 that had 2 big story expansions and Ultimate just piled all 3 parts of the story in one game.
I don't know if they did that too before, but I'm almost certain that for 8, they were legit different games (the PS4 went straight for a compilation with both vanilla and xl in one disk but not the PS3, IIRC, and vanilla alone didn't come out at all on ps4). Dunno about 7, I didn't play it.

Yeah, that and it's even easier when they just have to port Ultimate to all the new consoles, like on Switch (still waiting for the European version of that, I really liked Ultimate's full story)

Several developers of visual novels and games with erotic content on Steam have recently been hit with warnings from Valve threatening to remove the games from the store unless the game is updated to remove said content. Affected developers include HuniePot (HuniePop), Lupiesoft (Mutiny!!), Illusion (VR Kanojo), Neko Works (Tropical Liquor), and more.

Several developers and publishers, including MangaGamer (Kindred Spirits), spoke out against Valve’s sudden change of mind. MangaGamer mentioned that they were wholly in the dark with the latest apparent policy shift, and that the game would never have appeared on Steam in the first place if they hadn’t confirmed it with Valve representatives.

Developer Lupiesoft protested the sudden move as an attack against visual novel makers, and pointed out perceived double standards in terms of what counted as sexual content, as games such as Grand Theft Auto and The Witcher 3 have not been hit with similar warnings.

New update: HuniePop's dev, Mangagamer (Kindred Spirits) and more got emails from Valve, saying they should completely disregard their previous emails and that this whole thing was just a mistake by Valve. Valve are re-evaluating numerous games.