You may come across a scenario where you want to script the membership of Office 365 groups. Unfortunately there is no Office 365 group admin role that you can assign within exchange online. You have to assign global admin permissions to any account that you want to be able to modify Office 365 group memberships. This problem is has a UserVoice page here.
Microsoft has a few powershell commands that you can “supposedly” run to “Find the permissions required to run any Exchange cmdlet”. However when you run these commands on Add-UnifiedGroupLinks and Remove-UnifiedGroupLinks, the role that they specify that you use is: Mail Recipients. So even after assigning the Mail Recipient role to my specified script user account, the commands do not work. Go Figure MSFT!
My only workaround at this point is to simply assign my script user account to be the Office 365 group owner. Once this is done, this user can add and remove group members within exchange online powershell. Of course this only works in limited scenarios, and still needs an admin to assign ownership permission to the script user.