From the PR update: https://www.anthropic.com/news/updates-to-our-consumer-terms

“If you do not choose to provide your data for model training, you’ll continue with our existing 30-day data retention period.“

From the support page: https://privacy.anthropic.com/en/articles/10023548-how-long-...

“If you choose not to allow us to use your chats and coding sessions to improve Claude, your chats will be retained in our back-end storage systems for up to 30 days.”

it seems really badly designed or maybe it is meant to be confusing. It does not make it clear that the two are linked together, and you have to "accept" the both together even though there is only a toggle on the "help us make the model better" item.