That page is referring to their password breach detection feature though, not password sync. The sync pages have language which indicates that the encryption is only end-to-end if you use a passphrase. See:
> With a passphrase, you can use Google's cloud to store and sync your Chrome data without letting Google read it. ... Passphrases are optional. Your synced data is always protected by encryption when it's in transit.
https://support.google.com/chrome/answer/165139?hl=en&co=GEN...
> With a passphrase, you can use Google's cloud to store and sync your Chrome data without letting Google read it. ... Passphrases are optional. Your synced data is always protected by encryption when it's in transit.