I cannot say for certain what the reasoning was behind the depreciation, but seeing as clEnqueueBarrierWithWaitList() was added at the same time, it was likely just renamed to clean up the API and avoid confusion with clWaitForEvents(). The only difference between clEnqueueBarrierWithWaitList() and clEnqueueWaitForEvents() that I can see is that clEnqueueBarrierWithWaitList() adds the ability to create an event that allows querying the status of the barrier.