Hello @Bhargave, Shripad ,
You can continue using ADAL libraries for authentication, but it's important to note that Microsoft has deprecated ADAL. While existing applications using ADAL will continue to work, Microsoft will no longer release security fixes for ADAL after June 30, 2023. This means that your application could be at risk if any security vulnerabilities are discovered after this date.
As for the Azure AD (v1.0) endpoint, it has not been explicitly stated how long it will be supported or if there are plans to decommission it. However, since ADAL is deprecated and no new features will be implemented, it is advisable to migrate to the Microsoft Authentication Library (MSAL) to ensure continued support and access to the latest security features.
For additional Information you can follow document: Migrate applications to the Microsoft Authentication Library (MSAL) , Microsoft Entra recommendation: Migrate from the Azure Active Directory Authentication Library to the Microsoft Authentication Libraries
Hope this information helps. Let us know if you have any additional queries. Happy to assist you further.