Windows 10: Join AAD with powershell
At present there are no PowerShell scripts for joining devices to Azure AD.
You can upvote the feature request here and subscribe to keep track of updates from the product team. https://feedback.azure.com/forums/169401-azure-active-directory/suggestions/20399941-all-powershell-bash-script-azure-ad-join
You can, however, create the Group Policy pbjects with Powershell. See this similar thread on Spiceworks: https://community.spiceworks.com/topic/2021904-automate-joining-a-computer-to-azure-ad