iCloud can appear your iPad only when Find My iPad feather was enabled, and the iCloud account was same as the iCloud on iPad, or we can’t use iCloud to erase disabled iPad. It’s very important for iDevice users to enable Find My iPhone feather when set it up in the first time.
If Find My iPad feather was disabled, you can force factory reset iPad to unlock it.
Or use the Eelphone iPhone Unlock tool to fix disabled iPad in clicks.