John Vogl of The Athletic: The last time a trade happened where slots were swapped including the top pick was 2003. That is when Pittsburgh and Florida did the deed. In most cases, this does not pan out well.
Some of the returns on these trades certainly did not pan out. When Washington did it in 1975 for essentially Bill Clement, Clement was traded off to Atlanta after just 46 games. The pick they also got played just nine NHL games.
Then there is Florida, which was on both sides of this in the early 2000’s.