In Skype for Business, setting Set-CsUserServicesPolicy -EnableAwaySinceIndication:$false removed "Away/offline since" timer visible for other users.
In EU (Germany specifically) this timer is seen as privacy-intrusive, and this needs to be configurable in Teams as well.
Currently Teams explicitly don't allow to remove this (https://docs.microsoft.com/en-us/microsoftteams/presence-admins#admin-settings-in-teams-compared-to-skype-for-business)