We know you are patiently waiting for this feature. This feature is being implemented in stages. Fast tenant switching is currently in testing both internally and with early customers. We expect to release to the public in the Fall. I’ll post an update once it’s rolling out.
Full multi-tenant, multi-user support will be added after fast tenant switching.
Please check “Teams/Skype Consumer chat and calling interop” on the public roadmap at microsoft.com/microsoft-365/roadmap?filters.. for updates.Ronald van Ackooij commented
That would be great news, however I'm unable to find it in the Microsoft 365 Roadmap.