First off, there is actually a dedicated forum category for stuff like this …
The problem is readers don’t look there, and staff doesn’t seem to use the category much at all.
Users are posting in the Warehouse issues category …
I like the idea (of notifications) but there is plenty of room in the margins for announcements.
Main issue is that the forums are hosted by Discourse.org, so this may need a plugin.
There are sometimes warning banners on the top of SketchUp Help Center site pages.
The EWv2 is now running on the common Warehouse backend.
Since it’s web-based it can just display a “Oopsie Panda” page.