This actually sounds more like lean startup than unlike it. Yes lean startup encourages getting to testing your ideas quickly, but it also focuses on reducing p

This actually sounds more like lean startup than unlike it. Yes lean startup encourages getting to testing your ideas quickly, but it also focuses on reducing process waste. If you have a mature product and enough data points suggesting major new feature, I think it'd be a waste to try and recollect those data points or build half of the features just for the sake of being lean even if in the past you have been mostly spot on with taking customer feedback and releasing successful major features based on them.