Donner went on to state that the characters were “always essential” to X-Men but “there are other stories to tell.”
That movie wasn’t well received, and one of the biggest things its failure highlighted was that many people wanted new things from the X-Men.
This is overall good news.
James McAvoy is rumored to be returning as Professor X in the latter two – it’s currently unknown if Fassbender is done with the series or not – so it seems that while their friendship won’t be a driving force, the characters will remain.