AK92 - It would be helpful to know what conditions you are modeling. Height, reinforcement length, soil properties, toe or back slopes, embedment, etc.
Lateral deformation can be a function of the base to height ratio and various external stability considerations. Most MSE walls I have observed that experience intended settlement do not displace laterally very much. However, I have seen lateral displacement happen with unintended settlement (the design did not expect a lot of settlement) where the wall will move laterally in conjunction with vertical movement. A wall built on a marginal fill slope comes to mind where there is less confining pressure and density on the slope side. Not sure how one would predict this ahead of time if you did not expect it.
There is a resultant force on the foundation from a reinforced wall with shorter reinforcement that has a X and Y component to it which could predict some lateral movement. Once a wall starts moving, the forces have to reconcile themselves in some manner. However, when major settlement is expected, reinforcement lengths tend to be longer to satisfy stability considerations thus that concern is minimized.