Does mirroring vertex character with Shapekey in edit mode mess up the deformation?

I’ve imported a game character with preset of rig and shape keys. The character is filled with triangular faces and I’ve cleaned up using tris to quad however there are still plenty of spots around the corner of each regions model and I tried to clean up the remaining however I find it time consuming to look for ways to remove tris and reconstruct the edge loop without losing the vertex that was in placed.

So I managed to finally cleaned up half side of the model. If I delete the other side of the model and duplicate it to flip in the x direction, would it causes to dysfunction the rig and distort the deformation of the shape key that’s been duplicated??