It’s only unlikely because you are basing your probability off of the data you know now, which in general is a sane strategy, but we’ve seen that the 1500m has been almost impossible to predict a year out.
2016: Centro. In 2015, Asbel Kiprop became the global champion for the 3rd time. He ran a PR or 3:26.69 which was over 2 seconds faster than the next faster runner and about 5 seconds faster then Centrowitz, the eventual winner in 2016. Centrowitz was unlikely a year out.
2017: Elijah Manangoi. In 2016, 12 men made the Olympic final. Manangoi was not one of them. Manangoi ran 3:31.19 in 2016 but ran 3:28.80 became world champion. Manangoi was unlikely a year out.
2019: Tim Cheruiyot. Tim ran the fastest time in the world in 2018. Tim had also placed 2nd in the previous world championships. Tim was likely a year out.
2020 / 2021: Jakob. Coming into 2020, Tim had just run the fastest time in the world in both 2018 and 2019. He punished everyone in the WC2019 final in probably the most dominant win in the modern era. But then covid struck. The 2020 Olympics were pushed back. The additional time allowed Jakob to mature into a contender. Jakob was unlikely a year out of 2020.
2022: Wightman. In 2021, Jakob was 1 month shy of his 22nd birthday. Wightman had just finished 10th and has just turned 27. Wightman over 6 seconds behind Jakob in the Olympic final. Wightman was unlikely a year out.
2023: Kerr. Wightman had just run 1:43 / 3:29 and Jakob had run 3:27 in 2022. With the previous 3 global champions all returning in 2023, it was very unlikely that Kerr would win. Kerr was unlikely a year out.
2024: Hocker. In 2023, Hocker was 5th, well off the lead. Kerr had just won the world championship Jakob had run 3:27 low. The entire world and media focused on the two man showdown. Hocker was unlikely a year out.