Are you backing up Office 365? If so how/with who?
Microsoft says they have replication and backups but somethings they can't recover for you. There are some companies (mostly ones I've never heard of) that offer backup services for Office 365 but I don't know how I can trust them. Do they need nearly full access to your tenant?
On top of the security concerns they seem like they cost more than my great value Business Essentials license $5/month/user. For clarification I'm not referring to business continuity as I don't know if any of the backup services will spin up new Exchange servers or SharePoint if Microsoft has an extended large scale outage.