This might be immaterial (no pun intended!), but saying a fare no longer exists seems silly to me. A fare is not a physical object. It's not like a sweater, where if the retailer sells them all, there really are no more to be had.
A carrier can charge whatever it wants, whenever it wants. Someone in the company has the authority/ability to sell a seat at a price that is no longer on public offer - even if that someone ends up being the president. This all seems somewhat ridiculous.