Consumer accounts did not disable basic auth (and have no plans to do so in the near future.)
Are the messages being sent but not received or is Sage unable to send them?
The first issue could be spam filters on the recipient side - recipients need to check the junk mail folder in their mailbox. It's also possible that Microsoft filtered it as junk - this is more likely if you send a lot at once.
What OS are you using? Is Sage installed and sending from your computer? They also disabled TLS1.1 and 1.0 around the time it stopped working - but it only affects Windows 7 (and older). If you are using a cloud-based version, this would not apply.