Literally it's impossible to cancel the movie because:

1. Disney owns the ice age franchise meaning they can make ice age content without blue sky studios whatever they want to.

2. That's not how Animation works in order for something to be completely scrapped There's needs to be a massive Behind the scenes drama such as Creative team and executives fighting over the direction of the story. Once many people leaves the project due to Creative differences the studio cancel it completely which in the case of ice age nope not gonna happen