By default, when restoring Gmail data, all labels that were ever associated with the backed up emails will be restored. Additionally, a newly created "Restored (date)" label will also be assigned to all of the restored emails.
So, for example, if you are restoring a group of backed up emails that had the "Inbox", "Label A", and "Label B" labels, the restored emails will have the "Inbox", "Label A", "Label B", and "Restored (date)" label assigned.
If you want the restored emails to not have any of their original labels assigned (i.e. only have the 'Restored (date)' label), then deselect the 'Add Original Labels' box, as shown in the screenshot below:
Please note, however, that if the emails you are restoring are still in the user's Gmail account, and you selected to not restore original labels, all of the existing labels on those emails will remain attached. Spanning will simply add a new 'Restored (date)' label to these existing emails and mark them as unread (which may trigger a 'new mail' notification).
Please note that if you are restoring emails where 'Spam' is one of the labels, then these restored emails will only show up in the 'Spam' label in the user's account. This is the existing behavior of Gmail, as anything with a Spam label will not show anywhere other than in the Spam label.
Additionally, you can customize the 'Restored (date)' label to anything you like. This feature can be useful if you are transferring backed up emails for a departed employees Gmail account to another user's account. You can customize this label as shown in the screenshot below:
If you have any additional questions, please reach out to firstname.lastname@example.org.