I'll admit the forced opt-in with no possible test period was a bit of an odd implementation, but I'm not sure how that was all handled...whether that was the role of Bing or Esri. However, since the new basemaps had been up on Bing Maps itself for quite some time, I would imagine the color scheming issues could have been anticipated.
And I'll speak up and say that I like the new basemap. The old road map was absolutely heinous with those yellow state borders, this is much more clean and professional. And the labelling in the hybrid basemap seems fine to me.
I wouldn't suspect there's a way of switching to the old version since Bing rolled this out via an opt-in phase first, then the stage we're now in, in which this is the "only style served up through all Bing Maps outlets".