What is the point of ‘git submodule init’?

Reading the git submodule documentation, there is a use-case that ostensibly justifies the existence of git submodule init as a standalone command. If a user who has cloned a repository wishes to use a different URL for a submodule than is specified by the upstream repository, then that user can:

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)