The new “Notify when available” feature in Teams notifies you when a colleague becomes “available.” 

🛑 Unfortunately, privacy protection (=disable) is not available. However, you can set the duration of your own status

to avoid constant changes (notification trigger when changing from „available“ and „offline“ )

–> https://support.microsoft.com/en-us/office/set-a-duration-for-your-status-in-teams-d82c5629-96a8-44e9-bced-2925470e0d96)