Explanation
The impact of creating a Contact without a parent Account is that Contacts are public to all users, potentially sharing sensitive data. This is because Contacts without a parent Account are considered as private contacts, and they do not follow the sharing rules of the Account object. Private contacts are visible to all users in the same role or above, regardless of the Contact owner or the organization-wide default settings. This can expose sensitive student information to users who should not have access to it. Contacts without a parent Account are not private only to the record owner, at risk of ownership data skew, or require manually creating a related Affiliation record to enable sharing. References:
https://help.salesforce.com/s/articleView?id=sf.contacts_parent.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.contacts_sharing_considerations.htm&type=5