Rename or make changes to an ad placement
If you rename an ad placement, you will lose any existing advertiser bids for that placement. This functionality is to ensure that we provide a good experience for advertisers as well as publishers.
If you add or change the page location of ad units in a placement, you won't necessarily lose bids for that placement. However, we encourage you to update the description and, if necessary, the name, to ensure that your placement is still accurately represented to advertisers.