I'm not a lawyer, but this actually makes sense to me. The copyright on the page is to copyright the page as a whole. When you update the page at all, the new p

I'm not a lawyer, but this actually makes sense to me. The copyright on the page is to copyright the page as a whole. When you update the page at all, the new page would be copyright when you update it, and while the old page was copyrighted before then, you're no longer showing that page and so you would no longer show the old page's copyright date. As a result, the copyright became a decent heuristic for seeing how recently the page has been updated. Then I think some people, recognizing the use of the copyright as a heuristic, would then update the copyright without updating the page just to make it seem like the page has been updated recently. That's easier than actually updating the content of the page, and the only downside is giving your page a more recent copyright date in the notice. I'm not sure what this does to any copyright disputes though, but I think most people consider copyright disputes more unlikely than someone perceiving a page negatively due to the older copyright date.