This IS working as intended. The whole purpose blizz made it like this is because of the tactic that a lot of guilds use (2 groups on either side of Saph, to avoid stacking blizzards) Occasionally the ice block would be on the same side twice, so everyone on the other side runs to the slime.
Also, this works anywhere on the grating on the floor, at the edge of the room. Not just the chambers. Not and exploit. WORKING.AS.INTENDED. This has been working since old naxx (if memory serves) since we had a lock run there somehow and not die. If it was an 'exploit' it would have been fixed by now...
EDIT: Your argument saying "it isn't working as intended, that would be stupid" makes zero sense. You're essentially saying that ways to make fights easier is stupid. I.e. Moving to the wall when Shade does his arcane explosion.
Nevertheless, this should be moved to guides - as it is a nicely laid out guide..but still not an exploit :-/