Doesn't this Wikipedia article answer your question? It says, in particular,
Azad Jammu and Kashmir, abbreviated as AJK and commonly known as simply Azad Kashmir, is a region administered by Pakistan as a nominally self-governing jurisdiction.
(I added the bold face.)
I can no find evidence that these companies have a specific policy about Kashmir in particular, but the enforcement of their community standards have been perceived as censorship on multiple occasions.
Here is an article on the Guardian from 2016 where several users describe Facebook account terminations which those users felt were not justified. In some ...