Actually, it has never changed. Like you, it came as a surprise to learn this when I first joined FR.
Most Catholics think that Vatican II did away with the requirement of not eating meat on any Friday of the year. Most think it is now just Ash Wednesday and the Fridays of Lent that we cannot eat meat.
This is what the new Code of Canon Law brought out in 1983 says about the matter:
Canon 1251
Abstinence from meat, or from some other food as determined by the Episcopal Conference, is to be observed on all Fridays, unless a solemnity should fall on a Friday. Abstinence and fasting are to be observed on Ash Wednesday and Good Friday.
Canon Law still requires that Catholics not eat meat on Fridays!
Of course, most Episcopal Conferences have determined that, instead of abstaining from meat, Catholics may perform an act of penance of their choosing. But, do you ever remember to abstain from a particular food or do some other penance on Fridays? And, at any rate, the main rule is still to abstain from meat on Fridays, the performance of another penance instead is an optional alternative.
It says “or some other food”. Did Catholics always have a choice?