It seems to me that even the Aruch Hashulchan (and R’Moshe) wouldn’t hold of this heter nowadays. Boruch Hashem in recent times hair covering has become the norm it most frum communities.
Most, but not all, so there’s certainly a nafka minah.
Also, I wonder, since the reason for the Aruch Hashulchan’s heter is that uncovered hair is a common sight, if the fact that it’s common among non-frum women makes it okay, or is it talui in frum women.