[anaximander]

I think they're pointing out that while the speed of the earth relative to the sun is 30 km/s, its speed relative to the center of the galaxy is quite a bit faster, which may be a fairer comparison to what's being discussed in the original article.

[thraway2016]

They're not even remotely comparable. Tangential speed x where r=several thousand light years results in SUBSTANTIALLY less centripetal acceleration than the same tangential speed where r=a few AU.