That's part of it, but the advent of the Wacom and the tablet, Photoshop and even the mechanical pencil meant that many generations of art practice would be replaced by new ones, that were not necessarily informed by what had come before it. In many ways, people who started drawing in the digital era have a completely different mindset to their predecessors.
Contrary to what many might think, art technique does influence style, and thus how many themes and subjects are depicted, because different techniques inherently have different qualities and appeal to different kinds of people. For example, With photo-manipulation software turned art tool, digital composition became possible, but with undo commands, layer separation and the limited colour space, as well as working on a screen as opposed to paper and cel, a different mindset would develop on a very deep level regarding what values and preferences would be accepted.
There's also a disconnect for some people when you essentially have mix-media animation, with traditionally drawn frames, digitally composited and intermeshed with CG-elements, whereas older productions all relied on completely hand-fashioned production methods (from first concept to final frame shooting). This often results in a stiffness and disjointed presentation if not handled carefully. A very skilled craftsman can of course work around most of these things, but it is nevertheless a starting handicap for many artists, especially those who grew up in this era with no prior experience or first hand knowledge of what come before it.
EDIT: Of course, that just the animation/compositing alone. A lot of things have changed with pre-production processes, music, sfx and writing as well.
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