NPR and BBC both report imperialist talking points of their respective governments as fact without the slightest hint of criticism.
Far left would be Democracy Now, Jacobin, Mother Jones, The Nation, etc.
When it comes to that, the WSJ news section is arguably closer to centre-right than AP or Reuters. I think there are a microcosm of tiny complexities within the categories.
[0] e.g. https://www.bbc.co.uk/bitesize/guides/zgh9ycw/revision/3
I'm not sure that's a left/right issue, unless it happens to be the 1950s (there are some surviving imperialists on the right, and ~none on the left, but I wouldn't expect the _average_ Tory voter to be too gung-ho about how great the empire was...)
Also, that site is a GCSE revision site; I think that's just the history curriculum. And nothing seems particularly over-critical on the page you linked.