The details of Hilchos Eiruvin are highly complex and technical.
Rav Ahron Kotler z”l was of the opinion that Route 9 (Madison Ave) is a Reshus HaRabbim Diyoraysa, and therefore would invalidate any Eiruv made that crosses over Route 9. According to many Poskim, this could invalidate the Eiruv if it encompased certain streets that lead into the 9. The lakewood Rabbanim have never countenaced an Eiruv that would be invalid according to Rav Ahron’s shita. There are many, many smaller Eiruvin throughout Lakewood that are Kosher according to all. And are approved of by many of Lakewood’s Rabbanim, (including some of “Yeshiva’s 4 Poskim”)
This does not necessarly relate to the Shailos involved with the creation of an Eiruv in Brooklyn, and RavMoshe z”l’s Shita regarding the “Square” containing 600,000. This is a unique issue relating to Route 9, which transverses most of the eastern seaboard of the US.
This isn’t really a political discussion, and should probably not be made into one.