I'm afraid you are mistaken. I was there this afternoon, and all of the signs show a 7:30 opening. I confirmed it with a Skyliner cm.
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The Times Guide says it was scheduled to open at 6:30 am this past Sunday, for one day only. Perhaps you saw the sign on Sunday.
I recorded the trip from Epcot to CBR with a GPS tracker app on an earlier visit, and it was 12 minutes, with a couple of slowdowns but no stops. It's possible cm's are being told to add a few minutes to allow for brief delays.