Currently, a lot of the dinosaur sounds are the same. I don’t believe it’s a bug that they are that way.
Could they maybe diversify sounds between dinosaurs? Sure, but that’s an embellishment that doesn’t affect gameplay. If it were to change I think that will be much later, after making sure that bugs are fixed, adding more dinos and tweaking their stats… etc.
I know the change seems simple and quick, but they can’t just take pre-existing sounds, either. Ludia might not have the rights to use them, and Universal might not still have them, or want to hand them out/have them be used. And creating dinosaur sounds from scratch is not as simple as getting a dog’s bark or cat’s meow. There’s no real reference or recording to use, and they don’t have a library of pre-existing data all ready to use for each of these dinos.
tl;dr Could they add more sounds? Yes. Is it worth it? Will it happen? Maybe, but probably not any time in the near future.