Just because you donate money doesn’t mean the charity or nonprofit (or whatever OpenAi is), can do as they like. They may still be committing fraud if they are not using the money in the way that they claim.
(Not a lawyer, obviously.)
I don't understand the framing of your question, is it "since he donated, he didn't expect anything in return, so he is not harmed no matter what they do"? Kinda seems like people asking for donations should not lie about the reason for the donation, even if it is a donation.