With the newer versions of Outlook 365, when creating a new invitation, a Teams Call link is automatically added to every meeting, which might not be wanted by some customers. Here is a quick way to disable it for the whole tenant:
Connect-ExchangeOnline
Set-OrganizationConfig -OnlineMeetingsByDefaultEnabled $false
To check out if the settings has changed:
Get-OrganizationConfig | select OnlineMeetingsByDefaultEnabled