As it has been announced earlier in September, a new functionality is being rolled out to Office 365 users (Exchange, SharePoint and OneDrive) to provide relationship information using LinkedIn (now part of Microsoft).
If you want to manage this feature – i.e. enabling or disabling it, you need to go to your Azure AD administration portal (https://aad.portal.azure.com/) – the management option for this feature is not available in the Office 365 administration portal.
Once logged on to your Azure AD administration portal, reach out the Users Settings section (available through the Users and Groups section)
And finally, disable (or leave enable) the LinkedIn Integration option available at the bottom of the blade
if you have leaved this feature enabled, then each user has the choice to use it or not by connecting their LinkedIn account with their Office 365.
Knowing this feature will use publicly available information on LinkedIn.