There are two aspects that typically are different from Linux and other UNIX flavors on AIX:
1) When one user runs "sudo passwd <otheruser>" to update the password of another user, the other user will have to change the password on next login. This would not work with PAM managing the password and using accounts for auto-login. We would not want the PAM user to enter a new password. To avoid this problem the UNIX target application type has additional logic for AIX devices and runs a "sudo pwdadmin -c <otheruser>" after changing the password for another user. This will avoid the new password prompt on next login. But this logic only kicks in when the target application is configured with UNIX variant "AIX".
2) The new password confirmation prompt may different.
Typical Linux/Unix passwd command dialog:
~]# passwd capamusr
Changing password for user capamusr.
Retype new password:
passwd: all authentication tokens updated successfully.
Here the password confirmation prompt is "New password: ". Another typical form is "Re-enter <user>'s new password:"
These will match the default regex PAM uses to verify that the passwd command responds as expected and doesn't report an error.
But on AIX devices you may see a confirmation prompt like
Enter the new password again:
This will not match the default regex in PAM releases 3.1.1 and older. It will match the default regex in PAM 3.2 and up.