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.
An error occurred while saving the commentMichael commented
You can access educational organisations that have been attached in Teams Admin/External access +Add a domain.
I have another tertiary institution I access from my Teams dashboard via a drop down menu. You will need IT Admin or GA Admin to set this up. I can click between tenants at will.