Kersee had a ridiculous notion that 50.68 in 400 hurdles was anywhere near the equivalent of 47.60 in 400 flat. That explains 2023.
She'll go back to hurdles as priority next year. Paulino is a greater obstacle than Bol, especially given the otherwise stagnant nature of the 400 hurdles field, while at 400 flat there are wild cards like Miller-Uibo and Eid Naser and Adeleke.
Sydney did what logically projected, run roughly 2 seconds quicker at 400 flat than 400 hurdles. Likewise Bol's personal bests at outdoor 400 flat and 400 hurdles are almost exactly 2 seconds apart. The springy shoes and aggressive stride pattern enable not much lost in translation over the barriers.
The 400 hurdlers who fall apart late in the race, yeah they have a 3+ second gap between flat time and hurdles time. But you've got to be a monumental fool to project 3+ seconds to elite hurdlers. That was the same nonsense that proposed Warholm to 43.