Unlikely. Fassbender, McAvoy, Lawrence, and Hoult exist as far more than just the younger versions of those characters. They are established and popular characters in their own right.
The same would be true of Young Jean, Young Scott, etc, unless their characters were botched in some way or they were turned into afterthoughts. Give the audience reasons to care about them and they will.
Michael Fassbender/James McAvoy gave great performances. But still Patrick Stewart is still the definitive Professor X and Ian McKellen is still the definitive Magneto of this X-Men movie series. Go open a comic-book from the previous decades or the new ones, you'll see what I mean.
In my opinion, Kelsey Grammer is still the better Beast while Rebecca Romijn is still the better Mystique. That says a lot especially the younger Beast appeared in more better movies than the older Beast. And just because Storm/Cyclops got the shaft in the previous films, it doesn't mean the younger version of them, are automatically gonna be better.