Noticed that too. Is this their way of competing against the ULCCs on the route without cutting into business revenue? Ignoring the fact, of course, that the ULCCs often have better optionality than Delta's basic economy (free cancellations for a credit up to 60-90 days in advance, often under $99 cancellation/change fees until less than 7-14 days in, option to purchase a seat selection at booking, etc.)