Just a prediction but I can see Chief Toad dying in the future.
Like Jiraiya he has been around since Part 1 and in general is a very likable character.
He has been in quite a few battles.
In his last bout against the Paths of Pain he got blasted and broke every bone in his body but still survived.
Also a recurring theme is passing on the Will of Fire to the younger generation.
Gamabunta has two sons, Gamakichi and Gamatatsu.
I can definitely see Naruto summoning him in a future battle or the current one against Madara and Obito.
So what will happen is he will die and then his sons Gamkichi and Gamatatsu will inherit his Will of Fire and become badasses like Naruto did with Jiraiya's death :D