As you already know, Office 365 provides a service dashboard helping you to be aware of any service issue.
That said, this service dashboard may be unavailable when the issue is affecting the authentication process (either authentication itself or MFA services).
Well, you can now have email notification when some services are degraded or are experiencing issue.
To configure the email notification, logon to your Office 365 administration portal (https://admin.microsoft.com/) and reach out the Health\Service Health blade
There, you will find an Edit preference option, shown just below the tabs
Enable the email notification and provide up to 2 email addresses as well as for which Office 365 services you want to be notified
I would recommend you add at least one of your IT support DL/Office 365 Groups or Teams 
Hello Benoit,
Do you know if this is being roled out in stages perhaps? or requires certain licensing. I was excited to stumble upon your blog post, but then checked and there is not the option to Edit Preferences (or even the Report an Issue) in my Service Health blade.
Thanks
Hi Nic
this is being rolled out to targeted tenant first – started mi-oct.
there is no schedule yet for GA; you can enable targeted release for specific users (including yours) while keeping other users in standard release
What will be the cause if the Report an Issue and Edit preferences are not in my tenant Service Health?
Please read my answer to the previous comment