When changing an Azure B2C email adress, do I need to change the UPN as well

Question

In Azure B2C with the GraphAPI I can change the email address of an existing user with a http PATCH command: https://azure.microsoft.com/nl-nl/documentation/articles/active-

Answer 1

Yes, there is no need to update the UPN field.

Answer 2

That is why (in my opinion) email address should never be the default. Instead choose username account option and email becomes a much easier field to deal with.