[psylockolussus]

But bringing a younger version of Cyclops, Jean and Storm would require character development and I feel like its gonna be too much. They are gonna introduce the younger version of Cyke, Jean and Storm, and later in the movie, you'll have to deal with the original cast, Sentinels, the process of time travel and Bolivar Trask.

Unlike with introducing a minor or supporting characters like Polaris and Dazzler, they could give them a role like Havok and Banshee in First Class and it won't matter that much because they aren't Jean, Cyclops and Storm. But if the younger version of those 3 didn't get enough focus and screentime because the movie also had to deal with the original cast then it could be a problem for the movie.