Before you guys try taking MF support to ranked
Please take a moment and think about a few things.
First and most important of all... Who was playing the MF support? Gorilla. I'm pretty sure you're not as good as gorilla is.
Second Why did they pick it? Probably to out range the Zyra. Did it work? Oh deliciously.
Third Ashe combos very well with MF because of the double slows and the picks that Ashe gives with her ultimate, allowing for you to use your E and ult and probably for the most part, get a pretty free kill. I don't think MF support would work too well with any other ADC.
Fourth Play it in a premade. Seriously, I have no problem with off-meta stuff. I play Support Rumble and sometimes mid-Illaoi and sometimes Top Alistar... or mid Ali. But I very rarely pick these in solo-queue unless I'm 100% convinced that my rumble support will stomp the bot lane into the ground.
I am not discouraging you from trying MF support out. I will never discourage trying something out. And maybe... just maybe, we'll find out that MF support is the new meta. Who knows. You will never learn of new metas unless you experiment.
All I'm trying to do is help a few people think about their choices before they rush on to ranked solo-Q to try out something, because it worked at Worlds.
Good luck out there you guys.
Edit:
I completely forgot to mention the most important thing of all!
Do you have Arcade MF? If you don't, then your MF support is destined to fail.