Originally Posted by
mtkeller
Give me an example where a cheaper fare bucket is available but the more expensive one isn't? The only time I could see that applying is if you're booked in the forward cabin and are willing to take a downgrade to economy.
A cancellation of a ticket might allow a lower bucket to be available. Or maybe IRROPS. Although, I'm unsure if, for example, a T were cancelled, if it would still be a T or if that seat would become a Y.