The "all" pages are the "all layers", "all targets" and "all machines" pages. These pages have a filter that allows you to see: layers added / not added to a project targets provided by layers added / not added to a project machines provided by layers added / not added to a project Those filters include a counter, as all Toaster filters do. Because you can add / remove layers from these pages, the counter information needs to update without a page refresh (right now it doesn't update until you refresh the page).
I've got a non-angular based solution for this which seems OK to me (not great but is not too much of a hack either). We could land this for M1 and make sure that in the angular rewrite this is considered.