This feature allows Brave users to delete their previously-synced data from Brave servers.
Yes, you will still be able to user Brave Sync by creating a new chain once your current chain is deleted.
Yes. If you use the “Delete Sync account” feature in the latest version of Brave, all devices will lose access to the Sync account and the encrypted data will be permanently removed from the server. This happens regardless of which version of Brave is running on the other devices in the chain.
No. The data which was previously synced remains on each device. It just won’t be synced to other devices or to Brave’s servers.
No - you cannot recover your Sync chain once it has been deleted. This deletion is permanent and you will need to create a new Sync chain and have one of your devices re-upload the data.