Note: This is not a new problem and has been going on for a while.
If you log in via SSH when new updates are available or after installing updates, the MOTD doesn't reflect the last changes you've done... unless you log out and then back in again.
I logged in this morning as a user that doesn't have sudo access this morning and saw this in the MOTD:
8 packages can be updated.
6 updates are security updates.
So, I opened a second SSH session and logged in as my user that does have sudo access and saw this in the MOTD:
16 packages can be updated.
14 updates are security updates.
I installed these updates, and specifically to test this logged my non-sudo user out and back in on a separate terminal, which displayed this in the MOTD
16 packages can be updated.
14 updates are security updates.
I logged that user out and back in again and saw this in the MOTD:
0 packages can be updated.
0 updates are security updates.
*** System restart required ***
Is there some caching going on or some setting I need to disable to get this to be correctly up to date?