So, if anyone is aware of the reason for its placement, it would be most helpful to learn more about that before making the final decision whether to keep/remove it.
Because objectboxes and messageboxes and atomboxes have become opaque, so the stacking order of wires does matter more. They have to stay on top in order to be more visible, yet the pd architecture is not sophisticated enough to allow pd to force all of its externals to draw all boxes _under_ the wires.
Well, in that case the line in question is a band aid on the problem, not a fix.
Such a redraw call should not try to redraw all cords but only those that are visible, otherwise you get potentially excessive error outputs from tcl/tk reporting that there is no such cord/canvas (e.g. for the ones embedded in sub-patches) that bog pd down. If you have a large patch, you can get literally hundreds of those per every GUI update that eat precious cpu cycles.
There should be a loop that goes through all existing cords and checks whether they are visible and if so, raises them. Otherwise, they should be ignored.
Ico