I also think that Merab won that fight against Umar obviously and fairly. It not broken hand that matters, its skill that matters. If Umar was more skilled, he would not have landed that punch or landed it more precise or with less power. Its Umar fault that he has broken his hand. Should have eaten less and cut less weight that caused harm to body (hand) 
What is next for Merab? I dont know. At first I have suggested to move up, but there is a chance to face his friend Aljo one day. Then what he should do? Sterling move to other division again? Yan and Nurmagomevod could give Merab a good fight, but first seems to lose motivations (he is no where near UFC media, Petr seems to be enjoying his life and family), Nurmagomedov needs more experience (more fights). The rest of division - probably they could only make a huge upset if Merab does not stick to game plan, start playing and taunting.
What is next for Merab? I dont know. At first I have suggested to move up, but there is a chance to face his friend Aljo one day. Then what he should do? Sterling move to other division again? Yan and Nurmagomevod could give Merab a good fight, but first seems to lose motivations (he is no where near UFC media, Petr seems to be enjoying his life and family), Nurmagomedov needs more experience (more fights). The rest of division - probably they could only make a huge upset if Merab does not stick to game plan, start playing and taunting.