If a question that I voted to close comes around in the Reopen queue, is there a community standard for voting on it? Most of the time if the question is fatally flawed (lower-quality duplicate, clear and damning lack of details, 'do my homework') I will vote 'Leave Closed'. If the question is markedly improved it's more of a case-by-case thing. But I guess I'm asking if it's seen as poor form to even vote on such questions, as reopening is almost by definition asking for a second opinion.
If you voted to close a question and if are asked whether or not it should be reopened, there is no reason for you not to reevaluate it. And if it turns out that the flaws that made you vote for closing it remain there, then go ahead: vote that it should not be reopened. There is nothing wrong with that.