The Treasury roll is having an adverse effect on the pattern, as usual. Ultimately, the pattern will clear into or out of the Friday roll. We will be monitoring the model in both contracts but the "official" contract remains Dec. The pattern has moved up to the "turn up" level for 10s and Classics but has not confirmed a switch.
The SP (and NDQ) contracts will remain Dec for a while longer. Keep in mind that the structural nature of the product, the natural hedgers, and the zero rate roll down ALL contribute to a supported market during the roll process.