No pants clearly shows he's nonbinary-presenting: he goes by "he", but there's no external genitalia. Pants raises the question: what's in there? What are they hiding? Was someone uncomfortable with seeing a nongendered cartoon? Why?
I think it's far more polarizing to suddenly clothe him than to simply leave him as-is, especially since the design otherwise doesn't change. It's not "we're re-designing him and oh yeah there's pants now", it's "we want to make minimal changes but yeah we have to put pants on here now".
I don't mind furries and all, but who is the pearl-clutching retro-evolutionary end point that saw a cartoon animal with no genitalia and thought "oh my goodness, how sexual and provocative, cover this up this instant"?