When baby starts using hand in blw, will they refuse cutlery when they grow older?

No, I don't think so. As baby grows older, you can introduce cutlery gradually. Moreover, with social conventions in school and other settings like family meals, children usually have no problem picking up the habit of using cutlery. Even as baby is using his hands to eat, you can place a plastic set of baby cutlery by where baby eats and prompt him to use it :)