This is currently in Preview – planned to release very soon.
In the following weeks, Teams will be rolling out support on Safari 11+ on macOS. While in preview, there are known issues with Safari’s ITP mode and it is advised that users disable Safari’s Intelligent Tracking Prevention.Henrik Börjesson commented
can we start to test with Safari in Q1 2019?
The team is working on the API, and we will post as we have more information.
In the meantime, for Embrava, please note they have announced presence support for TeamsOnly mode with their version 5.2.16.