I haven't seen any details, but isn't this a pretty straightforward way of doing it? The non-profit has had majority ownership of the for-profit subsidiary since 2019. The already-for-profit subsidiary has owned all the ChatGPT IP, all the recent models, all the employee relationships, etc etc.
The cleanest way for this to work is the for-profit to just sell more shares at the $150B valuation, diluting the non-profit entity below majority ownership. The for-profit board, which the non-profit could still probably have multiple seats on, would control the real asset, the non-profit would still exist and hold many tens of billions of value. It could further sell its shares in the non-profit and use the proceeds in a way consistent with its mission.
They wouldn't even have to sell that much - I am pretty sure the mega-fundrasing rounds from Microsoft etc brought the non-profit's ownership to just north of 50% anyway.
I don't see how this wouldn't be above board, it's how I assumed it was going to work. It would indeed mean that the entity that controls ChatGPT would now be answerable to shareholders, a majority of which would be profit seeking and a minority of which would be the non-profit with its mission, but non-profits are allowed to invest in for-profits and then sell those shares; all the calls for prosecutions etc seems just like an internet pitchfork mob to me.