Gaon: “Even if the 1000 years shelf life of cherem R’G were up in 5778, does anyone really believe Yidden living in North America, or EY would start taking multiple wives, unless, of course, if we had a kol koreh from all the leading Gadolim authorizing polygamy as a means of addressing the shiduch crisis.”
That’s exactly what I said: 1) The gedolei rabbonim would need to reauthorize the practice of polygamy and 2) The gedolei rabbonim today have this right.
The mere concept of Yidden having multiple wives isn’t far fetched as even today there are living frum Yidden, (Sephardim, Teimanim, etc.), that have several wives they married in Morocco, Yemen or elsewhere in recent times. It has only been Ashkenazim who made a gezeira against it (the reason for which is disputed among the Seforim HaKedoshim), and the gezeira itself even for Ashkenazim had a preset expiration date.