That review is dated February 17, 2015 -- the day that Hamilton opened Off-Broadway. See paragraph six (right above the photographs)
You should look this up yourself, but here:
(And kindly stop spoiling the quiz for those who haven't taken it yet.)
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Well that was kind of a flawed question bc only one person actually said anything before the public saw it. And sorry about "spoiling" your quiz. I didn't realize that it's so important to you. It's not my fault you have a bad question.
First preview at the Public was 1/20. Opening night at the Public was Feb 17th. I don't understand this entire thread arguing and using spoiler tags with regards to an internet quiz, but "before it even opened" is correct here. It opened on Feb 17th.
I'm not arguing at all, it's just a poorly written question so I needed clarification, the OP was the one getting upset about spoiling the quiz like it's a sat test. NBD.
I didn't find any of the questions to be worded poorly. It was all very clear to me. Thanks for putting together a fun and challenging quiz, NewYorkTheater. Some people will always have a bone to pick but do know that most of us enjoyed and appreciated it!
I think the misunderstanding earlier in the thread was the difference between a show "starting performances" (previews) and "opening." (thus commencing "regular performances"  I'll admit that theaters seem to be doing their damnedest to erase the distinction between the two, perhaps in part as a way to lessen the impact of professional reviews.