I like where your head is at, but this is one of the pitfalls of the original PHB Beastmaster sub class that wizards had to correct. If your companion is just an actual living breathing animal it becomes very problematic if it dies. Not so much from a storytelling standpoint; that could be potentially good character development. But your companion is tied to your mechanical combat options. So you have to have a way to replace it. Not to mention how much extra programming/writing it would take to create all that content.
I think a fun workaround to preserve the vibe in BG3 while still addressing the main prob, would be if they kinda Planescaped it when the animal companion died. So the first time the animal dies, they could do a cinematic where the heavens open up and the animal returns from over the rainbow bridge. Like all done up proper with at least as much flare as we get from the various camp cutscenes or like getting hit in the head before falling off the nautiloid hehe.
Then the animal companion becomes like the spirit version with the magical bond that is all connected up to the Ranger and endures in that way. Perhaps a magic collar with a bell that only the PC can hear, and a deeper level of communication at periodic intervals. Done more narrative than direct dialog perhaps, but stuff of that sort fleshed into the story. In BG3 they have some freedom to riff, so it'd be nice to see something of that sort. Sure it'd be some definite work to create the content and especially the customizations, but then that's the sort of content I'm pretty into, so making more work for them on that one doesn't seem like a bad trade off. At least for where my heart's at with it hehe.
I think the Ranger really requires some extra animal something just to keep them interesting, beyond the woodland scout that looks and feels like a rogue here, since they don't have the same sorta fight like the older versions and even their starting getup is just a recolor right now. More animal flare at char creation or right afterwards in the early game would be cool.
