In this sentence, "het" refers to an action that is not necessary, so "it doesn't have to" does not work.
I can understand your confusion, though: since there is no literal translation for the verb "hoeven", it is unfortunately impossible to translate word-for-word.
EDIT: I stand corrected, "het" could also refer to the subject, though it would be a less natural translation.
I was refering to the translation of "Het hoeft niet". The offered translation is "There is no need" (in both languages not refering to anything specific).
My thoughts are that since there is no specific reference, it could also be translated as "It doesn't need to". This would also be part of a sentence that is yet lacking something specific.