A good first step would be to contact the profile managers to see if they have a source or a reason for linking to those parents. In this case, probably not because the biography actually says, "His parents are unknown." However, it is always nice to extend some courtesy before unlinking profiles. You may also want to check in with the profile managers for the linked parents to see if they know of a source for the connection. In this case, the parents' profiles seem to be unsourced so that might not be much help either.
In all cases, it is always a good idea to communicate with the profile manages before unlinking family members.