I’ll tell you why it went away. For the vast majority of people, this is not the expected behavior when middle-clicking anywhere on the page. Doing so is supposed to autoscroll.
The super annoying part is that no matter what you had selected, it would paste that into the address bar and if it wasn’t a url it would just to a google I’m feeling lucky on it.
I always thought it would make more sense for the middle click action to only occur when your mouse was over the address bar itself, at which point it would replace the url entirely or something.