Regarding the EntraID federation option described here (https://learn.microsoft.com/en-us/entra/identity/hybrid/connect/whatis-fed) - requiring organizations to implement/maintain additional identity infrastructure (i.e. ADFS or PingFederate) just for granting access to AVD is an awkward/impractical solution to say the least.
To further note, the need to offer external identities access to AVD is not just driven by the external facing customer scenarios but also applicable to organizations that leverage multi-tenants for creating the necessary security (identity) boundaries even for organization's own users.
TaniaMariscal / Microsoft PG Teams (AVD, Entra ID) - please incorporate this capability (B2B support for AVD) into the relevant product roadmaps.