"Is the non-profit still following its mission ..."
Who cares, that's not a legal requirement for a non-profit. "Mission" is meaningless.
"...and spending every dollar of donations and revenue on the mission?"
Again with the "mission". A non-profit does not net profit, that's what defines it.
"Does it need to retain all revenue growth? Why? ... it's a non-profit ..."
No corporation needs to "retain all revenue growth". There is absolutely nothing that requires a company to grow, non-profit or otherwise.
"It's just weird to look at it like you got shafted because your donation didn't "buy" all the maximum earnings potential ... and that you wouldn't hold a stake in anyway."
And that he didn't "create" either, and that he doesn't decide what the goals are.
"This is the same weird argument people make with open source dual license projects, like you give something away to be used for whatever, but someone else does something with it and suddenly they "took" something from you. Nah your stuff is right there doing its thing, it didn't go anywhere, it's still doing exactly what it claimed to do. If you wanted a share of the future earnings you're in the wrong place sorry."
A remarkably apt analogy, one that won't be popular here. But Stallman's interest with the GPL was to do exactly what Musk is doing now, to enable him to declare what you will do with your source code. RMS and Musk, AND Altman, are all sociopaths and they all do the same things.