It is hard for me to square "This company is a few short years away from building world-changing AGI" and "I'm stepping away to do my own thing". Maybe I'm just bad at putting myself in someone else's shoes, but I feel like if I had spent years working towards a vision of AGI, and thought that success was finally just around the corner, it'd be very difficult to walk away.
I think the much more likely scenario than product roadmap concerns is that Murati (and Ilya for that matter) took their shot to remove Sam, lost, and in an effort to collectively retain billion$ of enterprise value have been playing nice, but were never seriously going to work together again after the failed coup.
This is the likely scenario. Every conflict at exec level comes with a "messaging" aspect, with there being a comms team, and board to manage that part.