you don't have to, but you can if you like, the stock brakes should still halt a 14 or 15 inch rim if you aren't driving insane. I have the escort GT with 10 inch rotors up front and the 13 inch rimmed escorts have 9 inch rotors up front. so a 1 inch difference.
what style of rim you going with the stock 14 inch escort rim or the stock 15 inch GT fan blade? I thought about throwing my spare set of GT rims on my LX escort so it is rolling on 15 fan blades instead of the dinky 13 inch steelies lol. but the GT is my daily driver so kinda pointless to put a good set of 15's on a car I don't ever drive
answering your question no you don't need to upgrade your brakes. it just might not stop AS fast as before but it won't be a danger at all.