New Teams: contact list is incomplete

Under the Calls tab in Teams--at least for tenants with a Microsoft Phone subscription--the primary field returns a phone number or a name. If a name, there is no option to select a phone number. If one clicks the Contacts button toward the upper right of the window, then a listing populates the window, which includes a search field. Many, many contacts are missing from the contacts list. All the missing entries exist in the Contacts module of Outlook, and at least guest users (haven't tried nonusers) appear if their name is added to the People field--but, as noted, one cannot then opt for their cell, office, or other number. This makes the New Teams completely useless for any organization that uses Microsoft Phone and works with external resources.