Well, they do reduce wages based on anything and everything that they can get away with. If they're already getting away with paying people $10/hr or whatever, I think it's easily plausible that they would realize they can now get away with paying them minimum wage. I don't think it's instantly rich people propaganda or a silly concern. Like for example, Wal-Mart among other places definitely pays less because they've factored in that people can go on government assistance and stay just barely above water even receiving drowning wages.
Like I say, I don't think it'll work out this way in practice (in fact I would expect that it would raise wages because it would reduce people's desperation and give them options beyond just taking whatever they could find for as many hours as they can stay awake) and it seems on the limited test like it doesn't. But it doesn't strike me as automatically a weird question or anything.