If they waited for the GPT5 pretraining to finish and then they minimized the cost of the loss of Altman and the engineers.
The whole secrecy, compartmentalization and urgency of their actions could only be explained by being against a wall. Otherwise if it was about ethics, future plans or whatever political it would happen at a slower pace.
Hope they involved their investors beforehand but I don't know if they had time, OpenAI probably still exists and evolves on other people's money. But what else could they do?
The OpenAI 501(c)3 already spun up a for-profit company in 2019 to do all the commercial work and take VC money.