Quite sure it is not just the "Chinese Law" being selective on implementation; seen elsewhere where charges of corruption being amended to blah blah blah.
Anyway, am able to access all the "banned" apps and websites while roaming with China Mobile (CMLink & eSIMHK) and China Unicom (Cuniq). This makes me suspect the ban applies to only local telco line holders (Chinese citizens) otherwise, why are roaming line holders able to access the "banned" sites via the local Chinese Telcos while local line holder can't even open the App or website? We are using the same network as the local Chinese in any case.
It is correct that the local Chinese Telco can offer internet services (non-restrictive) to company use, I use to work for a foreign company in China which apply for their internet to be non-restrictive so staff can use Google search, Gmail and Zoom etc.