Are Bulk API script updates pushed to copy_to fields?

Hi,

Let's say that I have a field a, that has copy_to set to field b.
When using the script property of the the bulk API, and I use the script to make a change to field a. Will the change be pushed to the copy_to field (b)?

Many thanks

Bert

Yes. Updates load the source modify it and then reindex. Copy_to is part of
the index process.