Managed account automatically linked to Microsoft account

[Trevor de Souza]

Hi - I have an email alias that is linked to a Microsoft account that has been used to setup a managed account within our Cloud environment. 

I logged into it.atlassian.com with the Microsoft PRIMARY account (which the above email alias is linked to) and it has somehow linked the PRIMARY account to the email alias.

How is this possible when we have not enabled or set up any Identity Provider or Authentication policy within our Atlassian environment?