Belfort is right, we very probably won't see Silva knock him or other people out with a front kick to the face again.
Is Silva's trademark a front kick to the face┐ - No
Is Silva's trademark a triangle choke┐ - No
Is Silva's trademark a KOing jab while walking backwards┐ - No
Is Silva's trademark a rear naked choke┐ - No
Is Silva's trademark KOing knees┐ - No
Is Silva's trademark a back elbow┐ - No
Is Silva's trademark a flying knee┐ - No
None of these are his trademark to win his fights frequently with, but he won at least once with one of these techniques and other ones, because his trademark IS to be an unpredictable multi dimensional fighter with the greatest accuracy to enter the octagon so far who doesn't have to rely on his right hook (or what ever technique) only. That's what made him going on a 14 fight win streak, 13-0 in the UFC, defending his title 8 consecutive times and thereby reigning his devision for half of UFC's complete history since UFC 64 so far.