Apple didn't raise prices in the UK immediately following Brexit, they waited for around 3-4 months (iOS device prices were raised and followed that with Mac and Accessory raises). They raised the prices in Europe in 2015 and again this year.
Trump won't be 'in' until 20th January 2017, so the currency may slide over that period and then some. That is 2 months, then there's the 'what will he do/say' period, so Feb/march 2017 for the currency to recover....
Will be very interesting to see what happens with global pricing, my general feeling is Apple won't reduce prices at all, they are aiming at being more elite with a premium price. When the boot is on the other foot I doubt they will oblige by reducing prices to sane levels, just like the Apple of the 90's.
(How the premium pricing strategy works when you throw compromised design in to the mix we shall see....but that is another argument for a different thread!)