I have a public ip address provisioned on Azure in the Region US East while all other resources are provisioned in the Region US East 2. For now, we want to avoid creating a new public ip address in region US East 2 to keep the ip address that we already got. My question is do my data send to my current public ip address with end up passing by the US East region then through the Azure backbone to its ultimate target in US East 2 region?
You cannot assign your public IP address which is in region A to any resource such as a VM in region B. So no, you need to create a new IP in region B.