Yeah sure, there definitely has been a history of bias in favor of British drivers and teams by Sky - no question. But they've also damn near revered Max as god since his first race in F1, so I don't totally buy his logic there.
Moreover, I think Newey is discounting the fact that people just have a strong tendency to root for the underdog or root for the fall of the king. Vettel was despised during his reign, as was Hamilton, and now largely the same with Max.