Panthro having 'died' is a pretty common plot device and most people watching would see it as such unless they just don't watch things much or know of the old panthro etc. If they reeeeeally wanted to get dark with the series I could see him as actually having died, but not for a show on cartoon network.
I do remember watching the original and thinking how Liono seemed a bit too adult given the backstory, and I admit that a coming of age story is very low hanging plot fruit; I just wish they could find a way to induce character development that isn't just 'he was a brat that learned to not be a brat'.
Ah well. Honestly, most of my quibbles are minor or things that could turn out positive in the long run. We'll see. I definitely can't complain too much about more anthropomorphic cats in cartoons...
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There is no shame in not knowing; the shame lies in not finding out