Originally Posted by RiotNome

Normal Elo was supposed to be hidden; its previous visibility was a vulnerability/bug in the system. Even if it had some positive benefits, for the good of the overall quality level of the game, it had to be patched out.

Bugs can lead to interesting emergent things, and sometimes they're eventually incorporated into the design (to use a genre example, see Tiny's Toss/Avalanche double-damage interaction in Dota), but in this case, having visible Elo is basically cribbing the functionality of a ranked queue, and that's an entirely different can of worms.