I think Altman must have worked in the past with lots of ycombinator founders to resolve disputes. Then to end up in his own, completely blind-sided and cut off. Nobody is immune to bad founder relationships.
Turns out the secret to getting through something like this is to simply have spent the past 15+ years genuinely helping everyone you've ever come across.
His CEO replacement supports him, the chairman of the board supports him, his investors (at least Satya + Kohsla) support him, his entire org supports him. You'd expect a handful of these people not to if there was really anything there, right?