I don't really expect any future Trolls media to reference the country or classical trolls, but I was expecting to see Barb and a few other rock trolls in Trolls 3. It was a real shame they weren't there. I didn't want them to overtake Trolls 3, I can kind of respect how much both sequels each kind of have their own vision.
Looking back I would have been content if they only got background cameos in the wedding intro. Maybe Barb is in a pretty torn apart, punk infused bridesmaid dress and actually gets to interact with Poppy for a little bit. Her Dad and Riff could be in the background, her dad is just asleep in his wheelchair wearing an ill-fitting tuxedo, while Riff is playing piano noisily.
As long as they're back again in the movie's outro and we could have seen them one last time, I'd have thought that was enough. It was pretty sad to see them absent.