Protecting against data loss is just as much a security measure as protecting from data disclosure. It seems unlikely anyone would advise against contingency plans. Having anything in a single location creates a significant risk of data loss. Emergency sheets and backups are your friends.
More likely, you are recollecting the debate on bifurcating credentials. Some people prefer a “belt-and-suspenders” style defense against data disclosure, keeping their passwords in one vault and their TOTP in a different vault. Others argue that one can do a better job of defending a single castle (e.g. with longer master password, MFA, short timeouts, etc.). Both sides have good arguments.