A dick will grow to the size that it was genetically pre-destined to grow to circumcised or intact. The lack of foreskin will reduce the volume of the penis by the volume of the foreskin that is not present. This may be enough to cause some visual size difference when flaccid but would negligible erect.
However, having said that - there are complications from circumcision that can result in circumcised men not achieving a full length erection. It is fairly rare, but some guys are cut so tightly the skin is taut enough to restrict their erection (which may be painful due to this condition). I know a few restorers that have had this condition have reported an increase in erection length after growing skin (and alleviation of the pain).
However, having said that - there are complications from circumcision that can result in circumcised men not achieving a full length erection. It is fairly rare, but some guys are cut so tightly the skin is taut enough to restrict their erection (which may be painful due to this condition). I know a few restorers that have had this condition have reported an increase in erection length after growing skin (and alleviation of the pain).