If your iPhone gets stolen as example and you erase the device from your iCloud account, do you still get your iCloud data on your new phone when you use the same iCloud account? Or will everything be erased on your old (stolen) phone and new phone as well?
Only the device you designate to be erased will be erased.
Erase a device in Find My iPhone on iCloud.com - Apple Support
Erasing the stolen iPhone using the instructions in If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support does not erase any data that was synced (e.g., iCloud Photos) or backed up (iCloud Backup) to iCloud and does not affect your new phone.
Erase iPhone device from distance
