Microsoft has announced that basic authentication for multiple email connection protocols won’t be supported after October 13, 2020. You won’t be able to connect with EWS, EAS, IMAP4, POP3, or Remote PowerShell unless you use modern authentication. There’s just over a year to prepare, but there’s some work to be done.
Microsoft has released a preview of the cmdlet set to allow tenants to create and manage protocol authentication policies for Exchange Online. It’s a great chance to disable basic authentication and reduce the attack surface for password spraying.