Looks like half a polybevel. I'm not sure why you would only want to add an edge loop to one side. I suppose you could boolean it again with a slightly larger object. But it wouldn't really be a true edge loop.
Avoid booleans if possible and you will get better topology (note ugly n-gons in your example). Bridging or poly extrusion will generally be all you need. Either of the two methods in attached Houdini file are better than booleans. If you have to use a boolean, I would then delete the ngon (third example) and rebridge the edge loops.
Edited by anon_user_38315714 - Jan. 27, 2022 19:31:15
Island I would then delete the ngon (third example) and rebridge the edge loops.
On my end there's a discrepancy between 19.0.383 and 19.5.303 in your third example. Did polybridge (default pairing shift?), or something else change between versions?