I'm pretty sure the answer to this is "not enough data" but I'd be interested in people's views and if anyone has talked about this with midwife/ob gyn.
My mother and aunts all had extremely fast labours. We're talking 2-4 hours from 'first twinge' to 'oh, look, a baby!' My sister was born on a very surprised nurse just inside the doors of our local hospital and two cousins at home before the paramedics arrived. All healthy babies and no dodgy cervixes.
Yesterday my midwife asked me if there were any fast labours in the family - I hadn't considered this could be a thing...is it? Knowing my luck I'll buck the trend and end up with a three day labour.. ;)