systemd reboot does not issue a wall message

I am not seeing the wall message when issuing systemctl reboot. According to the documentation, "systemctl reboot" is supposed to send a wall message (There is even a --no-wall option to suppress the broadcast message!). But the message is not coming at all.

Present behaviour:
root@abc:~# systemctl reboot
Connection to abc closed by remote host.
Connection to abc closed.

Expected behaviour:
root@abc:~# systemctl reboot
Broadcast message from root@abc
 (/dev/pts/4) at 12:44 ...

The system is going down for reboot NOW!
root@abc:~# Connection to abc closed by remote host.
Connection to abc closed.

Version Details:
root@abc:~# cat /etc/os-release
NAME="Ubuntu"
VERSION="18.04.4 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.4 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

root@abc:~# systemd --version
systemd 237
+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN -PCRE2 default-hierarchy=hybrid