The article contradicts this point:

"There will be another, less contentious privacy issue with your Messages requests to Bard. These will be sent to the cloud for processing, used for training and maybe seen by humans—albeit anonymized. This data will be stored for 18-months, and will persist for a few days even if you disable the AI, albeit manual deletion is available."

This person shard a report on this issue for Ireland's Data Protection Commission: https://eupolicy.social/@thatprivacyguy/111839553765828301