I stumbled on this earlier today and I figured some of you may find it quite useful as the focused inbox is utter trash.
https://support.office.com/en-us/article/Configure-Focused-Inbox-for-everyone-in-your-organization-613a845c-4b71-41de-b331-acdcf5b6625d?ui=en-US&rs=en-US&ad=US
Simply run the following powershell command after connecting to your 365.
Set-OrganizationConfig -FocusedInboxOn $false