Yep. Basic income means we can do away with minimum wage. Now let's see how much poorly-regarded jobs (like janitorial) end up paying when the free market really does decide.
This isn't a downside of basic income, there is always a floor on the amount you can pay for labour. If you pay below what the market expects you are only going to get the truly inept to do it.
Monetary supply/demand is a tiny bit more complicated than that.