and if the future is set in 2010-2013 or so, many years have passed since X3, so Rogue would haved mature all this time.
She cant be the same shy and afraid young girl all her life, you know? Lol
between X3 and Days of future past, if Rogue stayed with the x-men, she wil have had some missions here and there, and various danger room sessions, so DOFP Rogue CANT be the same Rogue as X3.
NO character can act the same as X3. Things have changed sooo much, and all the x-men inevitably have matured
Next Big X-Men Crossover
* 2017- X-Men: Age of Apocalypse
Edit: Forget about 2017:
Official announcement -> X-MEN: APOCALYPSE - MAY 27, 2016!!!!