The quote you posted just seems intentionally dismissive. The truth is that whether any content is political or not depends much more on the views of the audience than it does the content itself. Outside of ads that political campaigns would want to run directly, this means that twitter will be arbitrarily deciding what content is political (and therefor not allowed), and what content is non-political (and therefor allowed). The only possible outcome is that twitter moderates the content based upon whatever political perspective they choose to adopt for this.