It seems to me that the two things are not mutually exclusive, and more that every community is inherently political - if it isn't really aware of it, it's never been shook hard enough.

The political actions of communities come out of political consensus, which is exactly what's happening with this letter: people are trying to agree on political action. A "politics-free" community is just one where everyone already agrees, or nothing has ever come up for people to disagree over.