Victim blaming puts the blame on the victim. There is no judgement on the victim in the nihilist case:

If someone steals my juice, I only have my juice if I take it back. The blame still lies with the thief though, whether I take it or not.

It's not really any different from the widely-accepted idea among the left that the working class has nothing to lose but its chains. The purpose is to shift your consciousness towards being an actor in your own life.

This question kind of makes me think of how the idea of responsibility vastly mutates when taken from a vacuum of at least 2 people to civilization as a whole: in the former example, it's pretty easy to argue that the notion of "blame" lies on the laurels of who's "at fault"; something that a nihilist would reject on the grounds that one can only be considered "responsible" for the actions of the only being one has any real control over. In other words, you're only "at fault" for your own misfortune if you knowingly screw yourself over; with external circumstances and people not factoring in at all. For the latter, blame is easier to dole out due to how dependent we are on one another and how interconnected we are to vast populations across vast distances; for example, it would be correct to blame a ruler for any deaths that occur due to the inherently violent and oppressive nature of the state (though if one does not also blame the state actors involved, it is incorrect).

TLDR;

Does nihilistic thoughts imply blaming a victim for not having an ability to defend themselves?

No, because blaming implies the belief in a "moral failure". I feel like nihilists are aware that people don't actually have any control over external factors (including other people). The nihilist notion of: "You only have rights that you are capable to defend" is a critique of the concept of rights.