We didn't saw anyone who died in a sacrificial slab in the last flash... So, maybe if you die in a sacrificial slab your soul is sent to the new body? and it is supposed to be ironic, because in that case you are actually making a bigger sacrifice when you die in a quest bed?...Or... Or maybe your soul is just destroyed, maybe that is why it is called "sacrifical slab"?... ¿What do you think?

We saw Dave and Jake and Jane. And Rose,Dirk and Roxy but not the ones that died on their slab.