Hired April 19, 2019 - so not exactly. Yzerman led them through 5 drafts and is starting his 5th season in Detroit. These are the prospects that have played in the NHL since he came in:
2019 - Seider 6oa (164gp), Soderblom 159oa (21gp)
2020 - Raymond 4oa (156gp)
2021 - Edvinsson 6oa (9gp), Sebastian Cossa blue chip G prospect.
2022 - Kasper 8oa (1gp)
2023 - total failure, no NHL games played.
6 2nd round selections made in 2019 (Tuomisto, Mastrosimone, Johansson) and 2020 (Wallinder, Niederbach, Hanas). None have really shown tremendous potential in the north American pros - Wallinder, Johansson and Hanas are developing well (but not dominating - per the Yzerman reputation). They're probably another 2 seasons away from being in contention for NHL roles in Detroit. The other 3 are looking like bottom 6 players after 3 years of development.
Signing guys like Copp, Compher, Walman, Chiarot and Holl to those contracts isn't great, but aside from Larkin and Kasper (freshly signed ELC), those are the only guys under contract for the 2025-26 season. Detroit has to ice a team that can look quasi competitive. They have 13 guys signed through 2024-25 (and 7 under contract beyond that). The next offseason will be where Yzerman really shows his stuff - with 37.5m in salary and half a team to fill.