Not sure, but could the gates be assigned on a 'first come - first served' basis or perhaps the first flights in get the bridges?
It almost seems as though there's competition for JB and AA to see who can nail the earliest JFK departure times lately. We departed JFK last week at 6:59 and arrived early due to good flying weather and we did have a jetway. The JB plane we went home on also arrived early and had a jetway. Last April we were scheduled for an upstairs departure to NY but the flight down was late leaving ergo arriving at SXM and they reassigned us to a downstairs gate after we had checked in. Like most others, I hate the downstairs departures, too.
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