They actually come out from the ally see the red arrow. This was confirmed by
@yulilin3 in 2016 at the party she attended.
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It has been my experience at many parties the dance crew generally stayed at the location in the red oval:
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This year is has been reported by someone they saw the crew dancing by the flag pole as seen in the video.
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If you have any photos
you've taken this year that contradicts the sighting and the video, please feel free to post them here. I prefer to keep my fellow DISers updated as many have expressed interest in seeing this performance with their kids. Disney can and has changed their protocols in the past and I'm doing everything in my power to provide as much information for them as possible.