I wouldn't at all make that assumption based on that press release. It's not uncommon for an airline to offer very low introductory fares, and you realize that these fares are valid for only a little more than one week in one direction, don't you? And it says "from $49." There may be only a few seats on each flight where that fare is valid.

A few years ago, Southwest had a fare sale of $25 each way systemwide and capacity controlled and was valid for travel for several months, not just 9 days. Southwest surely wasn't have trouble finding passengers.