Joseph,
Are you claiming that Rabbi Eisenstein claimed that Rav Elyashiv said he would invalidate a geirus on those grounds? Or are you extrapolating from the statement that such a belief is apikorsus to the situation of geirus?
I am extremely skeptical that Rav Elyashiv would invalidate a geirus on those grounds. (I am also generally skeptical of things said in Rav Elyashiv’s name that are not in print)