Originally Posted by
IADCAflyer
And my problem with this advice is that it's done at the airport where inventory has been massively depleted. They will tell you, take your coach seats or we'll gladly refund you the remainder of your trip.
On the contrary, most likely other pax will misconnect and this flight will leave with empty seats. That is the exact reason why many flights are overbooked but very seldom IDB or downgrade will actually turn out to be needed - keep mind that (most) airlines are actually very good at doing the math and has very little interest in downgrading pax.