Like I said before, I can't recall ever seeing this in any of the printed legislation (Chinese or English), except for when 48 hour TWOV was introduced in Shanghai, and then Jiangsu/Zhejiang (a massive area of land) were also covered.

While it makes logical sense to assume that the logic behind the Beijing policy extends to Shanghai, if the letter of the law doesn't prohibit leaving Shanghai, then you're not breaking the law by doing so.