Seriously?
Why samsung launches their flagships ahead of apple?
Yaris is City's direct competitor.. they can lose sales to upcoming city hence trying to make the best out of it before City hits the roads..
Civic & Corolla both have delayed deliveries and Toyota sort of enjoys market monopoly when it comes to Corolla hence no pressure there...
Early delivery of Yaris has nothing to do with customer centricity... its all part of business strategy to maintain a positive balance sheet in event of expected adversity in next 2 to 3 quarters.