Pretty sure they just gave Kofi the belt so he could lose it to Big E Langston soon. Dolph's had a couple matches with Kofi in the last few weeks where Big E attacks him after the match, so they needed it to be on a face instead of a heel.
I think they're building up to having the power trio all have titles. Dolph as the Heavyweight champ, AJ as the Divas champ (she won that #1 contenders match) and Big E as the US champ.
Kofi is just the guy that keeps the belt warm for the next heel they want to get over. The same reason they gave the belt to Sgt. Slaughter years ago. So that they could get the belt off The Warrior and back on Hogan.