From my perspective, it ended after the 1995-96 season. A bit of mid-1990s chronology:
*Scoring dipped below seven goals per game in 1990-91 and 1991-92. In an effort to boost scoring, the league announced the first obstruction crackdown. Scoring increased to 7.2 goals per game. That, combined with an 84 game schedule, resulted in a record number of 50-goal and 100-point scorers. But Montreal won the Cup that year, employing a mostly defensive system. They beat LA, who used the run-and-gun.
*The following year, two new teams (Anaheim and Florida) came into the league, employing defensive systems. Several other teams converted to defensive systems as well. Scoring dropped to about 6.5 goals per game. But there were still a lot of impressive numbers, including a 50-50 season by Cam Neely. Many enjoyed career years. The Rangers and Canucks reached the final, playing team games but favouring offensive hockey and a strong forecheck. Many expected a return to 1992-93 scoring levels.
*In the lockout year, scoring dipped to under a shade of six goals per game for the first time in many years. The lockout resulted in a condenced, 48-game slate, which led to many teams playing conservative systems. There were about 6-8 players who scored at a 50-goal or 100-point pace. Paul Coffey scored at a 100-point pace from the blue line in one of the best seasons by a defenceman in many years. Scoring did increase as the season progressed, and the first round averaged around seven goals per game. New Jersey used the trap, a strong transition game, team speed, clutch scoring and top-notch goaltending to win.
*After the prevalence of defensive hockey in the two previous years, the league renewed the obstruction crackdown. Scoring was at 7.2 goals per game early in the year, but levelled off as the year progressed and finished at 6.3 goals per game. The obstruction crackdown didn't last. However, the top players got their points, and lots of them. A lot of 50 goal and 100 point players. But the expansion to 26 teams had diluted talent pools, and most teams were only able to ice one strong PP unit, whereas in the 1980s, they could ice two. Colorado won the Cup playing a style similar to the Rangers in 1994.
*It all went to pot in 1996-97. Scoring plunged to around 5.75 goals per game. The trap became more prevalent than ever. Only three 100-point scorers. (Mario, Jaromir and Selanne). Detroit won the Cup with a skilled team, but their left-wing lock was about as run-and-gun as it got.
IMO, this is the season when the 80s era officially ended. It was dead and buried afterwards. Lemieux, Hawerchuk and Savard retired. Kurri, LaFontaine and Gartner retired the following year. Gretzky was 37. Many of the great playmaking centres and offensive defencemen from the 1980s were in their mid-to-late 30s. Scoring plunged again after this year, and hovered around 5.5 goals per game every year until 2003-04, when the bottom really fell out and scoring averaged under five goals per game for much of the year.