
Blu's tech dependency in Rio 2 wasn't a character regression but a logical continuation of his character growth and adaptation from the first film
Throughout the first film Blu is constantly shown to be dependent on human tech but even at the end when he learns to fly, he still didn't learn to be independent of tech. While learning to fly was a milestone for him it didn't help him learn other important things that birds need to know like foraging or building nests. They still live near a city so it was still easy for him to keep up his domesticated habits and the fact he could fly made it easier to get his talons on human devices. Rio 2 doesn't regress him or alter his character, it just accurately shows how there is more to being a free bird than flying and Blu still has a lot to learn. It even accurately shows how hard adapting to the wild can be for a domesticated animal. When Rio 2 came out I read the Poisonwood Bible for school and the family releases their pet parrot into the jungle who immediately dies from being caged his whole life. It also shows while Jewel is more trusting of humans, she's still a wild bird at heart and knows it's best for her kids and her mate to stop pretending to be humans and learn to truly adapt to the wild.