So just as the W212 E-Class and C218 CLS-Class received cosmetic changes so will the M-Class. It looks to be only the front lights and the front bumper receiving adjustment as the rear lights will stay the way they are.
The interior will also receive cosmetic changes likely influenced by the new S-Class.
What about the drivetrain? That also appears to be staying put. If you were about to order an M you might as well hold off a little bit before Mercedes makes your design outdated for the sake of change.