I think that the
drag0nf6y probably meant not that the scriptwriter must be talented, but that in order to write such an ending in a high-quality and interesting way, you need to work really hard. And not that Kirito found out about Asuna's betrayal and so on - and screw it. So, my women, come with me and have a celebratory threesome on this occasion! And they lived happily ever after)
It seems to me that for the author the main ending is the one in which Kirito turns into a cuckold(This also includes a bunch of dialogues with male characters in the first and second parts of the game, which say that when a wife cheats on her husband, it is normal. And Kirito's sudden craving for humiliation...
In general, I see it this way, that the author wants to make Kirito's first dream from the second part of the game come true in reality. Only if at the beginning of the game he screamed and woke up in horror, then at the end of the game he will cum "satisfied" at the same time(((