I think that's actually just bash messing with you. Bash implements it's own erase-word and binds it to whatever is set to werase in the terminal, so if you don

I think that's actually just bash messing with you. Bash implements it's own erase-word and binds it to whatever is set to werase in the terminal, so if you don't clear the werase entry bash will just keep rebinding it every new prompt. It's definitely not the kernel's doing - for example vim, which also uses raw mode, can use C-w just fine, and the functionality bash gives to C-w is different from what the kernel provides.