Nope. Britton Wilson is dealing with injury issues. Gabby Thomas is trading in some of her 400 strength for 200 speed. Athing Mu will probably not run the 4x400, because it's close to the 800. But if she does, she'll be too tired from the 800 to run her best 400.
That team wouldn't be able to break 3:16, never mind break the world record.
Maybe someone can correct confirm this but I do recall now he had ankle(?) issues at one point? Maybe he can't handle the intense speed on the curve in the 200 (the 400 being slower maybe stresses his legs less)?
This is right and the primary reason for him switching to the 100. His ankles are shot.
That could be true, I think too he has a mental block of not going out too hard. I think some diamond leagues after worlds of him really trying to push the first 60m would help. Honestly, it could be a physical limitation and he just is better linearly. The 400m, you don't have to push the curves.