Currently, the article_ui.extend_col_1 pluggable UI callback is only called once, when the Article Write Panel is first drawn:

In subsequent renderings of this panel after intermediate "save" operations, there is a short-cut bail-out branch:

This hampers plugins that want to extend this part of the UI for displaying volatile content.

I suggest extending the current article_ui.extend_col_1 events scope to fire the event when volatile parts of the write panel are redrawn as well.