Originally Posted by
stevenshev
It's a legal connection if it's on one ticket, which means we can infer UA expects you to make it the vast majority of the time. By changing now, you accept your worst possible outcome, so why not just wait and see if it works out as planned, which is how UA is underwriting things will go?
Why? Because the risk profile is different on separate tickets.
Also, it's not that UA sells the connection because it "expects you to make" a 55 minute connection, it's that UA's willing to accept the risk it will have to rebook you. That's not much of a risk from UA's perspective, but it can be a big hassle for the passenger, which is why most of us would also be thinking about contingency plans even if this itinerary were on a single ticket.