Cliffnotes:
-The title is officially Hey Arnold: The Jungle Movie
-All of the original children VAs will be returning, though will be playing different roles (duh)
-Arnold and Gerald will now be voiced by Mason Vale Cotton (Mad Men) and Benjamin Flores Jr. (Game Shakers), respectively
-The villain will be voiced by Alfred Molina
Source
Read up on the tumultuous history of the movie here, it's pretty fascinating
