What? Of course the newly exposed skin will be more sensitive as compared to before…for some time. We are talking about years and probably at least a decade after the circumcision took place, until it gets relevant for the affected person for sexual reasons. Until then the (probably even higher than before) sensitivity will have dropped. Sensors in the skin will be cut down by the body in order to prevent irritations when they have to fire all the time, which is true for the glans that is not protected anymore, is irritated all the time (underwear) and does not have the same capability to produce callus as the hands or feet.
The principle should not be foreign to you as principally the same happens by producing callus. The body produces it to stop irritation and to prevent long-lasting negative effects.