This ain’t a plot hole, a tailed beast is just a chakra, even if the jinchuriki dies, the chakra will fly from the body and eventually come back together
Maybe its jsut painful to die or maybe they become weaker idrk but no its not a plot hole since they just come back a few years later (Based on my estimates 10years 5years)
@Accountname0005 he did say once that if naruto dies he dies so im guessing that kurama would get reincarnated but not like at the exact time naruto dies