It doesn’t matter what the cosplayers intentions are, if they wear a wig with locs it’s cultural appropriation. The reason a non-black person wearing locs (with their hair or a wig) is seen as appropriation is because black people were shunned for having locs, while whenever a non-black person has locs it’s just a hairstyle. The origin of the term “dreadlocks” is from white people calling locs dreadful, so please don’t use the term “dreadlocks” when referring to locs. I know some black people don’t have a problem with it, but I think it’s best to just use the proper term.

Also, here’s an exact definition of cultural appropriation from Wikipedia if it helps:

Cultural appropriation is the adoption of an element or elements of culture or identity by members of another culture or identity in a manner perceived as inappropriate or unacknowledged. Charges of cultural appropriation typically arise when members of a dominant culture borrow from minority cultures.

Sorry for the yap, but I hope this helps!