Allow B2B Guest users to authenticate on Windows 10 Azure AD joined Devices
Allow B2B collaboration users (Guest users who signs in with an account that's managed by another Azure AD directory) login into Azure AD Windows 10 joined devices.
Use case: Collaboration between an educational institution and a public library. Adding student Azure AD (AAD) accounts from the educational institution as AAD Guest accounts in the public library AAD tenant would allow students to use their educational institution AAD credentials to login into the public library Windows 10 AAD joined devices.
Eddy Godts commented
Indeed, in school environments, too, it happens that devices are shared between students from daytime education and those from adult education. Often these users are located in different tenants.
This would also be great for large orgs where a central group manages Office 365 (and thus users' primary identities), but other business orgs mange their team's endpoints.