OK, it's now clear but I think the documentation could be modified this way,
since when creating a new user, one can set the password at the same time,
among other attributes.

This attribute specifies whether users must change their passwords when
they first bind to the directory after a password is set  or  reset  by
the  administrator,  or not.   If*pwdMustChange*  has a value of"TRUE",
users must change their passwords when they first bind to the directory
after  a  password  is  set  or reset  by  the administrator.

Note: when a user is created, the pwdReset attribute has to be explicitly
set to TRUE to force a password change at the first bind.