And not even close?
1976 Olympics was one the worst big hockey tournaments ever, quality-wise! (Arguably the worst in the 1970s.) You know that a tournament is poor when the West Germany ends up winning a medal (bronze); they never even got close in any other tournament, Olympics or World Championships. Sweden and Canada did not participate with any kind of team, plus USA had a poor team, and Finland one of its worst teams ever. Obviously USSR and CSSR would still have been the favourites, even if those other teams had had their best or at least a good team (minus Canada, of course, but it wasn't very realistic at the time anyway), but I think the overall quality of a tournament should matter in this conversation.
As for the Soviets, it saved some of their reputation in 1976, but I think the win at the
1978 World Championship (that you had #2) was the most important Soviet win up to that point, and it happened in the most hostile of places (for the Soviets), Prague. In the gold-medal game vs Czechoslovakia, they needed to win by two goals, and this they achieved - just barely (3-1). A loss (or a tie, or a win only by a goal) would have meant that USSR would have lost the gold medal for the third time in a row - a total disaster for Soviet hockey. And unlike at the 1976 OG, Canada and Sweden had teams present - not great ones, but anyway. Also, Tikhonov said that the 1978 WHC was the happiest victory of his career, even though USSR went on to win e.g. the 1981 CC, 1984 & 1988 OG, and numerous world championships.
BTW, In the game vs CSSR at the 1976 Olympics, USSR (just) needed a tie to win the gold... Yes, the game still had a fairly dramatic ending, and Kharlamov's GWG was a nice icing on the cake.