This item is still under review by the feature team. I have no details as to when a decision might happen.
This is actually the major hurdle I'm facing in moving my team from HipChat to Teams.
We're Mac-based; other applications (like HC) put a notification badge on application icon in the dock and the "alt-tab" (cmd-tab) list, in addition to the banner. An option to bounce the dock icon would be helpful but not essential.
We are getting closer… the team is almost ready to rollout MacOS notification support internally for testing – we hope to have it to the public by the end of this quarter.