From the article: this is why I can’t use MSTeams despite being an Office 365 subscriber:
> Another significant concern appears when organisations have more than 1 O365 tenant, often due to the result of acquisitions and mergers, inheriting additional O365 tenants, and users from each original organisation still using different tenants. Teams requires the user to login to a single tenant and can work in that tenant only.
> Although it is possible to have the users guested into the other tenant, and then they can switch tenants within the Teams user interface, so that they can collaborate with users in the other organisation, this is far from ideal as the user must actively switch between tenants before they will receive any notifications from that tenant, and cannot collaborate in 2 teams from different tenants concurrently. Also switching tenants can easily take 15–20 seconds to complete, so switching back and forth feels cumbersome too.
I’m a member of 5 different Slack tenants, 2 of which are free/open tenants (think: open-source projects). While Slack isn’t ideal (switching tenants in the desktop Electron app takes about 1-3 seconds) in Teams it will likely never happen because it’s counter to the Office 365 business model (I don’t want to be a “guest”, I want to be a first-class user in multiple tenants simultaneously - I need it for my work!)
> Another significant concern appears when organisations have more than 1 O365 tenant, often due to the result of acquisitions and mergers, inheriting additional O365 tenants, and users from each original organisation still using different tenants. Teams requires the user to login to a single tenant and can work in that tenant only.
> Although it is possible to have the users guested into the other tenant, and then they can switch tenants within the Teams user interface, so that they can collaborate with users in the other organisation, this is far from ideal as the user must actively switch between tenants before they will receive any notifications from that tenant, and cannot collaborate in 2 teams from different tenants concurrently. Also switching tenants can easily take 15–20 seconds to complete, so switching back and forth feels cumbersome too.
I’m a member of 5 different Slack tenants, 2 of which are free/open tenants (think: open-source projects). While Slack isn’t ideal (switching tenants in the desktop Electron app takes about 1-3 seconds) in Teams it will likely never happen because it’s counter to the Office 365 business model (I don’t want to be a “guest”, I want to be a first-class user in multiple tenants simultaneously - I need it for my work!)