Van Gogh painted it in an asylum (social safety net) run by Franciscans (repeal of anti-Church laws during the Third Republic) because he had self-admitted after cutting off his own ear (treatment of physical violence as a medical problem) because he owed money to Gaugin (private property). It includes an imaginary house and was painted from memory because he wasn't allowed to paint in his room (medical treatment in a total institution), but he was allowed to use a spare room in the half-full asylum which was normally for the wealthy (obvious). That said, he considered it a painting from nature, rather than an "abstraction", a form which was preferred by Gaugin in order to indicate harmony between man and nature (a fin de siècle concern which also directly lead to the rejections of liberal democracy and bourgeois society in the early 20th Century). On his own account, the subject matter of stars connotes a spiritual hope — and you can make what you will of the more specific religous and astronomical interpratations that came later.
In a narrow sense, there's no political art except electoral propaganda, in a broad sense anything made by humans is political.
So I don't find the game of definitions is not particularly interesting. It's not even that interesting whether the political content of art is intentional or self-concious on the part of the author or whether it's imposed by others. The process which I think is worth thinking about is the very second-order process we're engaging in now: who wants to make a claim about the politics (or lack thereof) of art, and why are they interested in doing that?
In this view authorial intent has a second-class position to its tangible effect.
[0] Also I feel the need to reiterate that I was expressing the possible opinions of a hypothetical person I made up, not my own.