More manageability to Unified Groups
Currently we have no idea how much Unified Groups site collection is used (size, usage) since O365 doesn't implement it. But in the future, this behavior will change and they will be counted as an usage of a site collection.
So, customer wants more manageability to know how much size they use right now via PowerShell or GUI. Also, they want to use UG site collection as free of charge since they are not counted as usage right now , or they expect better way of transition from free of charge style to pay per usage style (also, enough transition period)
The site that backs Office 365 Groups now supports quota management like other sites in SharePoint Online using the get-SPOSite powershell method.
mark fenemore commented
Ignite has been and gone but my latest conversation with helpdesk suggests no movement on this. We are really keen to deploy UG but without any control on storage consumption we are made to choose - have SharePoint Online storage management OR use UG. UG can not be considered fit for purpose until storage management is provided!
Spring and Summer have gone, and still no management and control. It doesn't matter how useful it is - we can't use it if we can't manage it, estimate storage costs, etc.
Christophe Fiessinger [MSFT] commented
Taka Groups storage leverages a SharePoint site collection so it's the same storage limit: https://support.office.com/en-au/article/SharePoint-Online-software-boundaries-and-limits-8f34ff47-b749-408b-abc0-b605e1f6d498
On the management/administration front we hear you and we'll have more to share at Microsoft Ignite: http://ignite.microsoft.com/session/sessionmoreinfo/?topicid=21c996f7-92b8-e411-b87f-00155d5066d7