Yeah.... it's not gonna go over well. Making it non-matchmade was a good move, but even if you can get a group of people you trust to do their job, Heroic Menagerie is gonna be PAINFUL. Firstly, extinguish. There was a reason this modifier got taken off the nightfall playlist, so why in Shaxx's name would you put it on an even harder activity?! WHY? Battling a 770 boss when the max you can be is 750 is bad enough, but to be sent back to orbit if you fail to kill it, or even worse, be sent back if you fail on the previous encounters, is gonna feel horrible. The other problem we may have... Blackout... Please, god, don't let this modifier make it to heroic mode. Otherwise, the Riposte and the Hunted are going to be damn near impossible to get done, unless you're literal gods. Hell, even the Crystals is probably gonna be hell and half with this mod on, cause of how small the room is. You can put any other mod on heroic mode, just NOT this one, Bungie. PLEASE.
Just don't play it. Once Bungie sees no one is playing it, then maybe they will learn something, doubtful, but maybe.