It is amusing to speculate on what would have happened if Hitler had sent troops into the Rhineland in 1936. Of course, as we all know what he did in OTL was much more clever: he simply proclaimed that the 14,000 Landespolizei in the Rhineland were hereby incorporated into the Wehrmacht! As he realized, France was most unlikely to have intervened to stop a "militarization" that did not immediately increase by even one the number of armed German forces in the Rhineland. Yet once the principle of remilitarization was established, Germany could and did then gradually add to their number.
I suppose one could imagine an alt-Hitler who was willing to take risks just to give a *dramatic* proof to the Germans that their "slavery" had ended--troops marching across the bridges, aircraft over the Cologne Cathedral, etc. But that's not the cautious Fuhrer of OTL