Jesus christ.. This is such a bad take from someone who obviously didn't watch any Wings games from the 89 season.
Though tbf this whole thread is filled with bad takes but this one is particularly damning. I just hope it's ignorance and not pure bias.
Watch games from that season and you will see that Yzerman was still very much a competent Sakic level two-way player in 89 adjusted for that era. The reason he scored so much was because of him back checking hard in the neutral zone and robbing players of pucks and being a master at puck possession. Mind boggling takes, really.
I think there's room for some nuanced evaluation here. As with most highly-skilled, offensive players who were depended upon to score, neither Yzerman nor Sakic were particularly good defensive forwards in their earlier seasons. But that's entirely normal and was probably by (coach's) design. (The Wings were so bad in 1985-86, and the Nordiques from around 1989 to 1992, that it wouldn't have made any difference anyway.)
I do think it's fair to say that Jacques Demers "took the reigns off" Yzerman somewhat in the 1988-89 and 1989-90 seasons, which partly explain's Yzerman's offensive leap in the former season. It doesn't mean Yzerman "sacrificed defence" or whatever the latest extreme opinion is, but the stats do tell a story:
Here's Yzermans
total on-ice goals-against:
1986-87 --
88
1987-88 --
75
1988-89 --
152
1989-90 --
166
This makes it look worse than it actually was because of his missed games in 1987-88. Also, some of the 1989-jump can be explained by Yzerman's killing penalties more, as his 1987-88 pace for PP-goals against was about 20, and in 1988-89 it's 45, while in 1989-90 it's 50 (either that, or he got worse at killing penalties).
Anyway, factoring in the games Yzerman missed in 1987-88 and also ignoring PP goals-against, his
ES (and/or SH) goal-against per 80 GP each season is like this:
1986-87:
74
1987-88:
75
1988-89:
107
1989-90:
117
The Wings, as a team, allowed 47 more goals against in 1988-89 than in 1987-88, so it would seem that difference was mostly when Yzerman was on the ice.
Given all this, and given that Yzerman scored 40 more ES points in 1988-89 than in 1987-88 while dropping from +30 to +17, I don't think it's unreasonable to suggest that his/Demers' strategy was more all-out offense in 1988-89 than in 1987-88, when the Wings had mainly been known for their strong team defense.
Of course, any suggestion that Sakic was "clearly" stronger for this flimsy reason is utter nonsense. We pause here to remember Sakic's -102 his first three seasons in the League...