Ring to their credit doesn't strip fighters until either retirement or when they relenquish belts at one of the weight levels. Joe is still WBC, WBA and WBO Supermiddleweight Champion. When he relenquishes the WBC, I guess Ring will wait until the #1 and #2 at that weight fight and then give them the Ring belt.
If he signals an intent not to fight at 168lbs again, he will vacate the Ring, that is how they work Otherwise Floyd would still have the Ring belt from 130 up to 154.