Harem - 1 Guy Many Girls
Reverse Harem - 1 Girl Many Guys
To my understanding:No MC being a girl and part of a harem is still Harem. Reversed Harem is when one woman has several men that want to have a relationship with her. That would those would be monogamous too would not change it.
Harem---> Players as masters NPC as Harem members
Reversed Harem---> Players as Harem members NPC as master
This conception was applied on "Era" type games for years already, It is an player-centered conception that serves players no matter the gender.
Your conception more likely to be an Social or Gender centered conception. One dominated woman as harem master and countless men as harem members only happned once in real world. It was the only female Emperor wuzetian who had a massive harem consisted by 800+ most famous men of time. She can do this because she was an Emperor not Empress.
Ah...I almost forgot. One American female prison guard also used naked Iraqi war prisoner men as Harem members. bad bad gal ^_^ Anyway, Nice to meet you my cultured buddies!