When hovering over the 'history' or 'excerpt history' links on (meta) tag wikis like this one, their color changes (you can see the difference below, I was hovering over the 'history' link). This makes you think they're clickable, but they're not; at least, nothing happens.
Only if you hover for a longer time, the reason for this becomes clear: the popup will tell you
This is the default initial version.
I'd like this message to be shown when you're clicking on the link as well (similar to how the edit button works now if you can't suggest an edit to a post), or alternatively make the links even lighter gray and not highlighting them while hovering.