People have publicly been warning this could happen. A few years ago, I wrote up some information about Cushing.
Cushing is something of a historic artifact. Oil futures contracts in the United States are based on the assumption that oil demand can be measured by how much oil is in tank farms in Cushing. Cushing originally was a stopping point for Texas crude heading North to Chicago, East to Tulsa and North to Canada. The growth in Canadian tar sands oil and fracking in the upper Midwest totally changed everything. Now the oil needs to flow South to Houston for refining or export.
The oil glut has had all of the tanks in Cushing 100% full, with plans to keep building more and more because of a pricing quirk called Contango. If the price people are willing to pay in the future is more than they’ll pay today, you make a guaranteed profit by buying oil today and delivering the oil in the future IF (huge IF) you can find a place to store the oil for a few months. The tanks in Cushing are ideal for this.