It does not matter whether a writer writes about any recognisable social or political subject as long as the quality of writing exceeds expectations. (Do you agree/disagree?)

I disagree for several reasons. Whilst attention to details such as the political and societal can add authenticity, writing will not always demand it. For example a short story will probably not have the room for it and a character driven story would likely delegate less time to such issues. 

In The Swimmer by John Cheever, there is a brief moment which touches upon the fact one of the couples are suspected communists. This fleshes out the characters and frames the story clearly in the context of the height of Cold War paranoia in America. 

In regards to ‘expectations’ it is first worth noting that the expectations of authors new and old will vary wildly and it is not the fault of the author if the reader has placed unrealistic expectations on them. Then there is the question of what ‘expectations’ mean as it could refer to quality and/or content. For the former I have already explained and for the latter, why would it matter if the content i.e. themes etc don’t meet expectations? If the narrative was well written then it proves that such themes are unnecessary. A person’s expectations do not reflect the quality of writing and nor should they.

Thus I disagree with the statement, certain themes do not have to feature in writing and audience expectations are wholly irrelevant.