There is no flows for shifts, like there was for staffhub. It would be great to be able to create flows from shifts for alerts and reminders, as well as emails for requests, and so on.
I haven't migrated my departments' staffhub to Teams solely because of the lack of MS Flow for notifications and array dumps for adherence to schedules and login/logout reports.
From my experience existing Staffhub flows will still work when migrated to Shifts. Actually it is still possible to use the Staffhub connector when you can determine the Shifts/Staffhub id (starting with TEAMS_). I was able to get my ids by opening Teams/Shifts in Chrome and use DevTools (F12) and the Network tab.
See for the workaround https://powerusers.microsoft.com/t5/Flow-Ideas/Enable-flows-from-Shifts-to-Office365-Outlook-Same-as...