I know this is a big ask, and wont be easy to implement (or quick), but it's becoming increasingly complex to manage many different Office 365 tenants. I have seen requests to include CSP billing, etc which is great but what I think we ultimately need is an RMM which fully assists with Office 365/Azure tenant management.
Step 1 on the list would be management of Alerts, issues, security problems, etc.
Regardless of anything else, I think this is of paramount concern. We shouldn't have a client calling us to tell us that they are locked out of their Office 365 account, only to discover malicious behavior from a strange location has locked them out. We should have a ticket on this, so we can research and resolve proactively (that is what we are supposed to be doing, right??) Alerts for mailboxes that are nearly full, compliance /data-leakage/PHI issues, etc.
Now, step 2 would of course be managing all of those policies, and being able to create groups and policies (similar to Group Policy haha) that would allow us to apply and change these setting or rules for many clients all at once. When new security options come out, or changes to security needs occur in Office 365, we want to be able to update the "default", or some sub-policy of the default, and have it apply to all of the tenants below. Conversely, if these policies change we need options to handle: Alert, Alert & Fix/Remediate, Alert & ignore (probably with some kind of escalation/approval).
Like I said, I know this is asking a lot, and I know there are some third party vendors which already do the mass policy management/changes... but the primary ask for sure, is management of alerting for each tenant, so we can take actions on issues well before they become a problem.