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.
Thank you for your continued feedback, the team is actively working on this item. We will share an update as soon as one is available.
Thank you for your feedback. The reply feature is currently being tested internally. We will share another update as soon as one is available.