We are not introducing any new Yammer group types at this point. We modified the existing Yammer group types to align with the group types that AAD supports. For example, previously you could have a private group where only admins could approve membership OR where any team member could approve membership. We removed the option to have any group member able to approve membership requests so that we're in sync with the O365 Group type offerings.
Thanks Adrienne but in the Ignite conference presentation on Yammer they directly referenced Yammer group types as something that was being investigated? Project/Communication/Announcement group are all directly referenced.