Yes GC4 was the first to offer “tournament edition” with the tight factory pockets.
But plenty of events had tighter mechanic modified pockets. I was just watching a US Open match from 1992 or 1992 I think it was Tommy Kennedy but I forgot the opponent. (The year after he won). The commentators were saying these were tight pockets and Pat was in the chat as well. They also said Leonard Bludworth made all the lights.
I’ll agree with all that factory tight pockets with extended rails are better than extra shims. But let’s not get carried away. Shimmed pockets don’t ruin the game. I’ve seen tons of action on triple shimmed GC’s where the players ran out and banked like butter playing both 9 ball and one hole.
Danny Bassavich came to my home room in about 1999 and played the owner (a pro) a few sets of 9 ball on the front triple shimmed GC. They broke even. Both played without any issue.