https://learn.microsoft.com/en-us/azure/sentinel/whats-new#connect-threat-intelligence-with-the-upload-indicators-api
"More details will be published on the precise timeline. New Microsoft Sentinel solutions should use the upload indicators API instead of the Microsoft Graph threat intelligence indicator API."
Deprecated in this case, means they are switching from one solution to a new one. https://learn.microsoft.com/en-us/azure/sentinel/connect-threat-intelligence-tip