That would put the pads on the wrong side. On a normal LED, the pads are on the opposite side of the substrate that the LED itself is on. On a reverse LED, the pads are on the same side.
For what it's worth -- attached are some pics of a normal Kingbright (e.g. non-reverse-mount) SMD LED I have from an earlier project; it's got equal sized pads on both top and bottom and they're connected. You're probably right that this isn't always the case but I just checked and all of the ones in my parts bin (Kingbright, Lite-On, a bunch of random China vendors) are this way.
