Assuming the above was in BOS, it seems like B6 is getting good use out of the three "swing" gates which can operate as either C or E gates (E1-3 or C5-7). I'm assuming it was one of those gates? Even on the Sunday before Christmas, when I was wandering over there before a 7 AM flight, all three of those gates were marked as having B6 flights as their next outbounds.
C5/E3 does end up being a long trek to the B6 baggage claim and/or check in at least by BOS standards (which means it's still probably shorter than many large airports!).