A question was presented to S&W and they answered the question.

Anodizing does not add strength. Anodizing is a process in which, at least in firearms, adds color, corrosion protection, and surface hardness to aluminum. The anodizing does add a tiny amount of thickness to the surface of the aluminum and also slightly penetrates the surface.

Re-anodizing can sometimes be performed, but the original anodized layer must first be removed. The removal of this layer may enlarge the holes in the receiver to the point that they will be slightly oversized even after re-anodizing.

At least that is my understanding of the process.