A few clarifications / my version of the timeline :
- MHJ was promised her own label from the start, it was just supposed to come latter on than it ended up.
- As part of the offer HYBE made her to recruit her, MHJ was also promised a free hand in the making of the planned Source GG.
- As such she took a personal interest in building that group and essentialy made promises/declarations on the basis of the promises made to her by HYBE in the first place.
- As the NJ project takes more shape, Bang declares that he isn't convinced by proto-jeans (sound/aesthetics/trainees blablabla) and starts planning for Le Sserafim (bringing Sakura and Chaewon, producing tracks).
- MHJ is pissed AF, threatens to take her ball and go home but is convinced to stay on-board with HYBE by being offered to have her planned label's creation pushed forward so she could debut NJ here wich she accepts (in part so she can fulfil the expectations/promises she had made to the trainess that would have gotten fucked over by the switch up of project)
So basically :
- Bang had to be strong-armed into debuting NJ (seed of resentment),
- NJ turns out to have all the potential in the world contrary to his previsions (narcissistic injury, resentment grows),
- NJ ends up deminating despite a complete lack of involvement from him while the group he build from the trainees up and produces for is stuck in the pack (narcissistic unjury², ressentement blooms).
Wich also explains the shareholder contract MHJ was under : she wouldn't be able to leverage it into a ~$100millions payout if NJ hadn't been so successful. A B or C-tier group would have given very little growth to ador (barely enough to cover costs), and MHJ would have ended up with the possibility of selling her shares back for barely more than initial price.
But NJ slayed, so bang is malding and hybe is risking having their financials get stress-tested the fuck out.
edit : you might think the money thing is more important than the pride thing, but the money thing doesn't explain why bang would send MHJ bitter texts about NJ chart-success, so I think the pride thing is actually a pretty big thing in this situation.