Yes. The description section of Debian's motd(5) manpage now reads: The contents of /etc/motd are displayed by pam_motd(8) after a successful login

Yes. The description section of Debian's motd(5) manpage now reads: The contents of /etc/motd are displayed by pam_motd(8) after a successful login but just before it executes the login shell. The abbreviation "motd" stands for "message of the day", and this file has been traditionally used for exactly that (it requires much less disk space than mail to all users). On Debian GNU/Linux, dynamic content configured at /etc/pam.d/login is also dis‐ played by pam_exec. Which seems pretty sane.