If you are concerned about the vintage of your camper, take a look on the title. It'll say 2013 or 2014. This is something beyond the control of the dealer, and will accurately reflect your TT's model year.
Camper design is an ongoing process. As materials from various vendors become available or are no longer available, changes are incorporated into the unit's design. If you assume that all changes are improvements, then it stands to reason that you should buy the last issue of any given model year run. Otherwise, enjoy what you have, and perhaps modify it whenever you come across a production change you like.
For example, there is probably no reason you couldn't install solid sliding doors in your camper, if you really don't like the folding doors.
2014 Coachmen Catalina 253RKS
2016 Keystone Summerland Mini 1750RD
2012 F250 Lariat 6.2L Crew Cab FX4
Reese dual cam SC/WDH