Can NTLM V1 disabled for On Demand Migration Directory Sync? (4382561)

Microsoft current stance on NTLM is as follow:

• NTLM V1 is already deprecated and no longer supported by MS.  Modern OS such as Server 2025 and up no longer support V1.
• NTLM V2 is in the deprecation phase, the next major version of Windows Server will have NTLM V2 disabled and no longer supported. 

On Demand Migration Directory Sync does not utilize NTLM V1 as long as the operating system supports NTLM V2. 

NTLM V1 can be disabled at the Operating System level via Group Policy.  Detail about the NTLM V1 Deprecation can be found at "Advancing Windows security: Disabling NTLM by default - Windows IT Pro Blog" and "Upcoming changes to NTLMv1 in Windows 11, version 24H2 and Windows Server 2025 - Microsoft Support". 

Once the operating system is configured to use NTLM V2 and V1 is disabled, we can confirm NTLM V2 usage via Windows Event log.  Sample logging is pasted below as reference.