Honestly with the amount of charity fundraising that reddit does, I bet they could pull it off. Just recently someone accidentally gave $15k to charity and in response, a bunch of users raised an additional $55k [1]. If they did intentional, annual fundraising with clear goals I wouldn't be surprised if reddit the non-profit organization could be self-sustaining.

But I'm just some guy on the internet who doesn't actually know anything about non-profits.

[1]: https://www.reddit.com/r/BestofRedditorUpdates/comments/1456...