To a first approximation, I'm inclined to agree with this reasoning. The main point of minimum wage (in the US) was to back-stop a buyer's market for labor from leading to mass deprivation among American workers. If UBI can guarantee a dignified minimum standard of living, minimum wage becomes redundant.
Hell, in a world of UBI, I'd anticipate volunteer organizations to flourish.
Hell, in a world of UBI, I'd anticipate volunteer organizations to flourish.