Duplicate Layers with sequential numbering rather than "copy"
When you duplicate a layer it would be much better if, rather than the XXXX copy suffix the duplicate layer was numbered. And preferably numbered XXX_0001 (or a format one could specify in the Preferences). This would make working with layers much much easier - especially when working with After Effects.
Perhaps you can use a free Batch Renamer script: https://github.com/creold/illustrator-scripts/blob/master/md/Artboard.md#batchrenamer
Sure the thing you are asking for should be available from the box though(Edited by admin)
Not an exact match for the custom numbering, but why not replicate what Photoshop does in Panel Options. The last checkbox in the dialog:
--- Add "copy" to Copied Layers and Groups ---
Uncheck that and it duplicates the layers and groups without the undesired "copy"