The engineering team is continuing to work on adding support for multiple accounts on desktop clients. We will first launch support for 1 work/school account and 1 personal account so users can enjoy Teams for work and personal side-by-side. Windows and MacOS. Support for multiple work accounts is still being worked on and will come at a later date.
You can track status via the roadmap here: https://www.microsoft.com/microsoft-365/roadmap?searchterms=68845.
This feature request is working its way through the backlog queue. No new details are available yet.
We are working on a design with more density in mind. Until this design is solidified we are putting this item back to Under Review.
This item is still under consideration by the feature team.