Hello @Amit Lal , Thank you for your patience! I got a response back from the team.
No specific date is established yet for Azure Application Gateway V1 depreciation. The team also mentioned that advanced notifications would be sent out before V1 support is stopped. This would follow the general Azure 3 year deprecation cycle post announcement.
Hope this helps. Please let me know if you have any additional questions or concerns. Thank you!
----------
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.