I just don't think it's logical for the breadcrumb to say message when on one of the four tabs. It would make more sense (to me anyway) for the breadcrumb to reflect the tab you're on.
"Messages" is the category of the resource, so that's really the same as elsewhere.
At most, you'd see the resource name in the breadcrumb, but that's OTT here because it's still the <h1> on the page. You wouldn't see "version history".
