I just found that the manufacturing date of my bike is September 22 2015. But I bought it at the Polaris dealer as a 2016 model on April 2016

Is my bike really a 2016 model?

On vehicles you can buy a "next year model" since the last months of the previous year. For example you can buy a 2017 Silverado on November 2016 with no problem.

Is the same with this machines?