They wouldn't just be giving in, it would take less than a day to get up and running on CloudFlare. That is probably worth avoiding $30k bill, especially for a non-profit.
As for PR, there absolutely is good will towards organizations that take on censorship. This is the #1 story on HN, so a company stepping in and saying "we got this covered, free of charge" not only shows they are good people, but also gives would be customers an idea of the quick implementation cycle for their CDN + the load it can handle.
Real world use case + helping to stop censorship = great PR