As you may know Azure Multi Factor Authentication is (or was as per the below) also available for on-premises deployment (known as Azure MFA Server) to protect your on-premises systems (like remote desktop, VPN, web server or Exchange).
Well, on July 1st 2019, Azure MFA will be no longer available for new deployment; existing deployment (aka activated Azure MFA Server) will continue to work and get updates and future version (but for how long).
If you were planning for Azure MFA Server, it is highly recommended to get your deployment activated before July 1st.
It is not clear on what will happen after July 1st if you have to redeploy an existing Azure MFA Server because of recovery