Microsoft's group-based licensing for Azure AD automates this process without using PowerShell scripts, per the document: Any new members who join the group are assigned the appropriate licenses.

Microsoft this month enabled organizations to assign Azure Active Directory licenses according to group.. Group assignment is perhaps a less tedious approach for organizations with lots of Azure AD ...

Microsoft switches on a public preview of Windows Azure Active Directory Group Management for administrators.

The new group licensing assignment capability is available for organizations that have a paid or trial subscription to Azure AD Basic, Office 365 Enterprise E3, Office 365 A3 or higher ...