Treat Galnet news like you would (or, I guess, should) treat real-life news. It's not "canon" in the sense that events actually absolutely happened that way. It's "canon" in the sense that it's actually someone's perspective on events.
Understanding that even the most objective reporting is, always and unavoidably, filtered through the perceptions and biases of the reporter is key; both in properly digesting the story of any good fiction, and in understanding the real world.
So when, for example, Galnet posts an article about how some accuses so-and-so of being complicit in the death of the Emperor, that doesn't mean it's canon that that person is complicit, it only means that it's canon that someone made the accusation that that person is complicit.