They did in Japan with the game Musou Orochi Z. It included both Musou Orochi (WO) and Musou Orochi: Maou Sairin (WO2) and added a few features & 4 new characters (2 truly "new" characters + 2 previously NPC)
Sadly, that was not released outside of Japan. Instead, some of the new features and the playable characters made it into the PSP version of Warriors Orochi 2.
However, PS3 is import-friendly if you have the ability to do so