This is entirely consistent with Wikipedia's existing policies on neutrality, because Wikipedia's neutrality policies apply to its encyclopedic content. The Wikimedia Foundation and participants in its projects have never been constrained by that particular policy, and are free to gleefully offer their opinions and pursue agendas. Indeed, the foundation is dedicated to spreading knowledge, and is opinionated about constraints on that goal.

No one has suggested, or is under the impression, that this notice is the same as an encyclopedia article. The encyclopedia article which ultimately covers this event will remain free* of opinionated statements, and instead describe the law, notable expert comments on its implications, the Wikipedia shutdown, reactions to this shutdown, and the stated motives of various participants, allowing the matter to speak for itself. It does not need to agitate for more freedom or pass judgement on the moral validity of the regime.

(* Wikipedia, being a product of mere mortals, will necessarily be an imperfect representation of neutrality. Nitpicking about this fact too much is minimally productive. People will do what they can.)