Although Provorov stands 6'1", weighs 218 pounds, and is left-handed defenseman that blocks shots and get physical when needed, he's a very mediocre hockey player. In many ways his underlying numbers are similar to defenders the Rangers have acquired or had interest in before, so it is totally believable that they'd consider signing him.
Here he rates out as primarily a third-pair defenseman, and at his age he's unlikely to evolve into something better. The consistency of his production speaks to the player he is, and that is a defender not worth signing.