Remotely deleting personal information from an old device

There is only a single tool for that - Find My. If you login to https://www.iCloud.com/find and it is listed, you can execute a remote erase. Otherwise, there is no means of doing anything to it remotely.

Erase a device in Find My iPhone on iCloud.com - Apple Support

Is your old device lost with your information on it? If it is lost/stolen then can you still see its location on the Find My app? If your old iPhone still logged into your Apple ID and is visible on the device list under your Apple iD?

Axel F.