Oh origins of the term? Main focus? Well then do enlighten me, but beware since I speak Japanese I will cut down any BS.
The main focus of Netorase was about the emotional journey the couple, most importantly, the emotion impact of the MC as they explore their sexuality. A heavy focus is on the distress of the MC as he experiences the actions taken place during the story. Some definitions would also state that the intent was also meant to bring out the emotions within the reader as well. There were no set roles such as "Bull" nor did it exclude other untraditionally relationships such as yuri, yaoi or poly relationships. You speak Japanese right so even you know that the word itself doesn't have anything to do with defined roles, or set dynamics other than One person that enjoys watching their partner sleeping with/having sex with another person.
Any tropes associated with the genre isn't an exclusive tenet of the genre and therefore aren't necessary.
This game is by definition Netorase, as it details the emotional journey of a cuckhold that gets off to seeing his gf interact with other people, regardless of that 3rd person's gender. Tori places a huge amount of detail into highlighting the emotions/feelings of the MC as all of this takes place. Terrace isn't necessary to the story at all for this to be a proper NTS, as it already is without his scenes.
The problem wasn't the dynamic introduced, it was that it completely clashed with what was being developed before that update. It felt extremely out of place and awkward.
How did it clash with what was being the developed when the overview has stated Ari was going to be the catalyst that pushes the couple forward from the very start? So according the game's overview she was always necessary in order to enable more intense action with Terrace, or at the very least speed things up.
According to Tori from his words on Discord, it was logical that fooling around with another woman would be a bit easier for Ayumi than to jump into doing things with another male.
As far as the toga party and that fake Zeus goes... I don't have a clue where that came from. I think I remember him saying he wasn't happy with that so who knows it it'll still be there in its old form in 2026 when we get back to that point.
