Four card limits were implemented in the 1990’s; I remember it when Ice Age was released.
What year was that? I found a 1998 tournament pamphlet and nothing about 4 card limits and still had 40 card minimum.
That might be a limited (sealed/draft) tournament, where you have to build your deck out of cards you get from packs at the start of the tournament. To this day, those tournaments have 40 card deck minimums and no 4 card limits.