I suspect it has more to do with anti-Semitism. The library profession from which I recently retired has always been very tolerant of anti-Semitism, and the current waive of anti-Semitism which is now considered normative in the WOKE community (and most librarians are very WOKE) is the most likely explanation.
While the NYPL public libraries are government agencies, complaining to the politicians probably won’t help as most of them are progressive Democrats who probably see closing the libraries on Sunday as a cost efficient way to show their dislike of Jews.