That’s a message from the Collabora base image that gets generated when a new upstream image is made available, but not a sign that there’s anything wrong with your AIO installation staying up-to-date. I imagine you’re using CODE v23.05.1.3.1 (I believe that’s what’s in NC AIO v6.4.0 latest at the moment).
A bump to CODE v23.05.2.2.1 has been merged into AIO so I imagine it’ll pushed out in the not too distance future (within the next couple weeks). You might be able to try it out by switching to the AIO beta channel, but that has obvious caveats.
Doing a docker pull on the upstream image won’t do any good - AIO builds its own collabora/code image based on the upstream.