@Maqbool Niazi Yes, once local AD users are synced to Azure AD using ADConnect and your WVD pool can communicate to your On-prem DC via VPN Gateway, all local AD users can login to WVD. While connecting to WVD, authentication will be done by AD Domain Controller. If you want to allow 50 Cloud users along with 100 local AD User as well, you would need to use Azure ADDS in that case.
Note: To allow users to access WVD, you would need to run Add-RdsAppGroupUser tenant.onmicrosoft.com WVD-Pool "Desktop Application Group" -UserPrincipalName username@your_domain.com for every user.
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