Problem statement
If a user links their social login identity (LinkedIn, for example) to their Database login identity (username + password) because they have the same email, what happens if the user then changes their LinkedIn email in Linkedin, then signs back in? Will their social login identity still be linked to their database login identity, even though the emails are now different?
Solution
If you change the email on one of the identities in a linked account, the accounts will still remain linked. In this example, the LinkedIn identity will show the new updated email after the next login, but the linked database account will still have the old email.