A lot of funding was predicated on them making the transition. Also they would not have been able to IPO without the transition, so there was a funding problem when you look at it that way.

I thought Altman didn't own hardly any equity.

I've also seen Open AI and Anthropic say it's pretty close at least. I'll try to follow up with a source.

They stated the total commitment is 1.4 trillion in their live stream about the restructuring and mentioned an IPO as the most likely path to get that amount of funding.

The non-profit controls the board of the for profit and can replace them at any time. They also serve in the for-profit board. This is according to the NY times article.