Perhaps a bit late to this discussion, but I thought I noticed most of the usual Disney social media mouthpieces had gone to Shanghai. Perhaps there is a bit of a to be expected disconnect with being in China.
Many, but there's still WDW Today, which is supposed to give several daily updates about the parks, and be available to answer guest questions. That's also not counting various businesses within the parks that have their own accounts, like Cave del Tequila or L'Artisans de Glaces.