Not necessarily.
In scenario 1 with no basic income the baker only receives what he is paid. If there were no other providers, and the baker would not desire to do this work he could charge more to stay and work.
This would apply until he has competition in one way or another.
In the second scenario, he receives BI, but the same market forces would apply and he would only be able to charge more as long as there are no competitors. Additionally, since everyone will receive BI this will grant people more potential free time. Time they could use to make their own bread in case the baker raises prices.
In this scenario the baker would have less incentive to work but would also have more potential competition in case he raises the prices.
