Re: X-Men 4: Age of Apocalypse
I think there's a way for Emma Frost to be in the X-Men team and in the modern (present) times. For example, she accidentally traveled to the future with Wolverine and the other people in DOFP.
X-MEN: DAYS OF FUTURE PAST
The future of X-Men's original trilogy cast begins this May!
Hugh Jackman - Halle Berry - Ian McKellen - Patrick Stewart
Anna Paquin - Shawn Ashmore - Daniel Cudmore - Ellen Page