The car buff in me much prefers model years for cosmetic/style change reasons e.g. being able to look at a car and say, that's a 2006 or that’s a 2010-2012 or that the first year for the new style XYZ model was 2015, etc.
I think a reason manufacturers use model years is because they don't want to be strictly limited to major redesigns being released on/around January 1st and still recognize the advantages of at least redesigns following a 'year' to 'year' identifier. If a manufacturer releases a significant redesign mid-year, they will have two very different looking cars identified by the exact same year. At a minimum, that can complicate things like future valuations (discussed in a separate thread here:
KBB, NADA, Edmunds and valuing Teslas).
Since model years don't prevent manufacturers from adding, removing or upgrading options/features/components during that year, I don't really see an advantage for using the calendar year to 'label' a car as Tesla does. Tesla wanting to be different is fine unless it's simply for the sake of being different with little or no advantage, or worse.....
potential disadvantages.
What am I missing?