For better or worse, we have several "Milky Way" skydomes. One of them looks much more like Center's shot. Either way, the skydome/texture used in Earth is called Milky Way, so I'm sure that was the intent.
Either way, those various Milky Ways are actually used in many maps. Not all, and often they probably get drown out by or interpreted as nebulae.
That explains so much.... I was wondering why there were so many BGs in foundry that were that shape..