Certainly, the news that Fox would like Lawrence, Fassbender and McAvoy to return to the fold doesn’t come as a huge surprise.
After that, performing a similar trick in order to have Lawrence, Fassbender and McAvoy pop up in a brand new timeline seems out of the question.
McAvoy and Fassbender have both been well received in their respective roles as best friends/arch enemies Professor X and Magneto and Lawrence has more or less revolutionized the role of Mystique.
With that said, if the three primary stars did return for a fourth X-Men outing, fans are unlikely to be too upset.