We use Conditional Access to limit the applications that Guests can use in our Tenant. We've recently enabled Planner for Guest access but have found that Guests also require permission the Group Service API in Graph, as documented here: Planner tasks and plans API overview - Microsoft Graph | Microsoft Docs
An assumption has been made that granting Guests access to the Groups service will allow Guests to read all our groups and get email addresses of the members. Is that a fair assumption?
