Obviously not MO, however. But I forget that in some people’s world, they don’t count. 🙂
It depends who, and it depends how broad a consensus they are bucking.
Besides, I’m not aware that the major rabbonim of Modern orthodoxy in the 70’s were in favor of the eruv. (like the Rav for example). If it was the entire torah jewry against a few MO rabbis, I think I would say they don’t change the situation.
“MO rabbis” are a broad spectrum. There are real talmidei chachamim, who are really yarei shamoyim, on one end, and there are some pretty dubious characters on the other end.