Is your feature request related to a problem? Please describe.
It's common to see people coming on discord with issues that can be fixed by upgrading their weakauras version.

Describe the solution you'd like
Show a message once per session when a newer version is detected, like details or bigwigs do.

Currently opposed as well, mainly because of the overhead of a addon msg channel, other ways to communicate it could be found, like coloring the version in the header in a different color or make it blink.

I always found those kinds of update nags to be obnoxious.

-1

Same, also not very keen on having that.