You are experiencing what I and many others here have experienced. I ordered my Mini Lite on Feb 28, 2015. It was built April 7, 2015 and when it arrived in June 2015, it was a "2016" model. What that really meant was that it was the same as a 2015 model built in late 2014, with a 2016 VIN.
Unlike the auto industry, the RV industry (Rockwood anyway) changes from one model year to the next in the spring, BUT they don't actually make any changes to the new model until late summer. So what you end up with is early models of one year that look like the late models of the previous year, and then the late models of that year have the changes.
1988 Coleman Sequoia - popup (1987-2009) - outlasted 3 Dodge Grand Caravans!
2012 Roo19 - hybrid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado 1500 Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10