In the 1960s and 1980s, Alvin wore an ankle-length sweater. In the 2010s, he wears a much shorter one. What were the reasons for this?
The Alvin Show (1961–1962) was an animated TV series about three anthropomorphic chipmunks named Alvin, Simon, and Theodore, and their human guardian Dave Seville. The chipmunks wore distinctive solid-color ankle-length sweaters. The follow-up, Alvin and the Chipmunks (1983–1990), made the art style more detailed but kept the same sweaters. The 1987 animated film The Chipmunk Adventure used the same character designs as the 1980s series.
At least four live-action movies followed starting in 2007, with a more realistic character design and size for the CGI chipmunks, lending a somewhat Chip 'n Dale look to their appearance. I'm ignoring these for this question because they're such a departure.
In 2015, the series was revived as ALVINNN!!! and the Chipmunks. The series keeps to the tone and character personalities of the 1980s series, as mentioned in a review in Anthony's Notes. And the overall character design of this all-CGI series resembles that of the 1980s, with a couple exceptions. First, the chipmunks are not as tall as in the 1980s series but taller than in the 2007+ films. Second, the sweaters are shorter, and you can see jeans under them.
Was there a reason for the change to shorter sweaters? Have the creators of the show said anything about it? It doesn't have anything to do with the longer sweaters resembling the traditional garb of the recently politically sensitive Middle East, does it? Or is it just hard to animate long, flowing clothes convincingly in CGI?