That category is vague and incredibly broad. It could include video games, CDs, DVDs, music, films, real and digital versions of books, magazines and so on, but there's little information on what it'll actually entail. "Overseas" was also specified to include Hong Kong and Macau.
Vendors found to be breaking the ban on "printed matter and audio-visual products" could be hit with between 12 and 48 point deductions. Getting 12 points deducted means a shop gets shut down for a year, and 48 points is enough for a Taobao shop to be shut down permanently.
The regulations seem to come from government regulations passed last year imposing a heavy tax on imported goods.
While this ban would be comparatively easy to enforce (do a search for "Horizon Zero Dawn" and get 5 full pages of stores, much easier than hunting down every last illegal scooter), it's unlikely to be rigorously enforced. That would cripple a sprawling, thriving and growing industry, and they'd never do that.