Its Pokédex Entry refers to them previously being slaves.
Both of these have a heavy note to HM slaves, Pokémon used simply to learn HMs.
Its previous Pokédex entry refers to it being a thief, which is a common racist stereotype about black people.
It can be seen as a counterpart to Piguson for multiple reasons.
The obvious cultural refence made by both.
They both have a base stat total of 440.
Piguson being a fighting type to counter Vandash's dark typing
Both of their shinies swap race.
For April Fool's Day 2019, Vandash was given a fake alternate form called 'Lawyerdash,' which gave the character purple skin, a dark purple afro, a briefcase, and a dark suit and tie. This made Vandash resemble the "Pool's Closed" avatar from 4chan's notorious Habbo Hotel raids.
Vandash resembles a human with black skin. Various other things in its design references many African American stereotypes. Its shoulder area is shaped like a watermelon, referencing the stereotype that black people have an unusually great appetite for watermelons. Its hair is a black afro, referencing how most people with the afro hairstyle are black people. It is also carrying a Poké Ball like a basketball, which is another stereotype of black people. Its shiny sprite is what seems to be a "Caucasian" version with the lips unchanged, referencing blackface.