So, we all know Brook got his shadow stolen and we know Moria prolly did it, couse thats what he told us.
Now if you think of it, that cant be, couse a shadow is coused by a solid object blocking light.
So I think we shuld not take it so litterly;
Brook still hase his shadow, but we cant see it, now why is that. Thats becose Brook wil vaporize ( or something alike ) if he enters light.
Makes sens so far ?
His shadow is not litterly stolen, but the prifilage of seeing his shadow is stolen, couse if he enters a light zone, he'll vaporize ( or what ever ).
Maby Moria eat some kind of "vampire" devil fruit, like we all know vampires are unable to exist in light.