I frequently hear Rav Moshe Feinstein zt”l’s opinion regarding Brooklyn eruvin being cited by those who have, unfortunately, gleaned their information from the Boro Park (1981) and Flatbush (1979) kol koreis and not from Rav Moshe’s copious teshuvos. Therefore, I feel that there is a need for the following reposting of Rav Moshe’s opinion as articulated in his teshuvos. I hope that the public will concur that the teshuvos supersede any kol korei.
Following the above, besides for the speciousness of the kol koreis, those who nonetheless want to follow the kol koreis have no right to impose their misguided personal opinions on others. [If there is a need for eruvin today according to Rav Moshe, see Rav Moshe Feinstein zt”l: The Need For Eruvin]
The teshuvah above confirms that Rav Moshe never issued a p’sak opposing an eruv in Flatbush but only stated his personal opinion since he recognized that his chiddush was not mentioned in the Achronim and that the Aruch HaShulchan did not agree with him.