Yeah, it was kind of BS for the NHL to allow all the new teams in one division, where one of the expansion teams was guaranteed a spot in the finals.
They probably did that for marketing purposes. If a new team has no chance at advancing anywhere, the local fanbase won't pay them any attention. Having an expansion team guaranteed to go to the Finals sparks interest and attendance.
Now with 31 teams, they can add new teams in where they fit best. I think they did it correctly back then.