They need substrate to be happy. If you decide to go BB Id rehome him.
From google
The yellow watchman goby prefers a "deep" substrate bed containing sand and rubble as it likes to dig. If they are kept with pistol shrimps the shrimps might dig out a burrow in the sand for the goby and the shrimp to live in, but providing them (goby and shrimp) with finished burrows made out of PVC pipes is usually a better option in an aquarium. Yellow watchman gobies get very stressed if they are not provided with enough hiding places.
