I don't think it was ever announced what role he is playing in the next movie, but Tobe Nwigwe has just announced that he has been called up to do some reshoots (which should mean that he is a human character, not a voice character).
I know that they gave themselves an extra 12 months on this movie, but that was more to do with stalling for a more global post-covid time that would earn the movie more money globally, not to give them more time to work on the movie. They were given enough time to have it completed for a June 2022 release, so for them to still be tinkering with it 4 months after that, every extra day working on it adds to the overall cost of the project, making it less profitable no matter how much it ends up making.
It also doesn't inspire confidence in the plot or visual effects if the director and/or producers are still not happy with the finished product, after working on the post-production for 12 months now (original filming ended October last year).